CN115349206A - Long-life laser diode package - Google Patents

Abstract

The present invention provides a high power, high brightness solid state laser system that maintains initial beam characteristics, including power levels, over a working time of at least 10000 hours without degradation in performance or beam quality. The invention provides a high-power and high-brightness solid-state laser system, the internal environment of which contains oxygen and does not contain siloxane.

Description

Long-life laser diode package

This application claims priority from U.S. provisional patent application Ser. No. 62/969,541, filed 3.2.2020, which is incorporated herein by reference in its entirety, and entitled to the benefit of its filing date in accordance with the provisions of article 119 (e) (1) of Chapter 35 of U.S. Farad.

Technical Field

The present invention relates to high power laser systems that provide lower wavelength (about 10nm (nanometers) to about 600nm, and in embodiments typically about 350nm to about 500 nm), wavelength laser energy, and uses of these systems and laser beams, including additive and subtractive manufacturing, material processing, and laser welding applications. The invention also relates to such a laser system and its applications, which provides a laser beam with a high beam quality and, in an embodiment, maintains a high quality and high power laser beam for an extended period of time.

Background

Infrared (IR) based additive manufacturing systems (wavelengths greater than 700nm, particularly wavelengths greater than 1000 nm) suffer from several drawbacks, among others, which limit build volume and build speed, as well as the overall efficiency and safety of these systems. Infrared beams are highly reflective of most metals and therefore couple poorly to metal targets or substrates, making them inefficient. Poor coupling also results in a construction or welding process that is difficult to control and may create health and safety risks with splashing, venting, and particle injection. The large spot size prevents the ability to achieve higher resolution in construction projects, which is further hampered by poor coupling and difficult process control. In addition, the life cycle of these infrared systems is very limited, with the beam quality degrading steadily over time, and in some cases rapidly. This degradation results in down time and also results in increased costs for repair and replacement of parts and lost production.

This degradation over time seen in existing infrared systems is also a significant problem for existing Ultraviolet (UV), blue and green lasers and laser systems.

In the present invention, unless otherwise expressly specified, "ultraviolet," "the ultraviolet spectrum," and "the ultraviolet portion of the spectrum" and similar terms shall have the broadest meaning and shall include light having wavelengths of from about 10nm to about 400nm, 10nm to 400nm, and all wavelengths within these ranges.

In the present invention, the terms "laser diode", "diode emitter", "laser diode bar", "laser diode chip" and "emitter" and similar terms shall have their broadest meaning unless explicitly stated otherwise. In general, a laser diode is a semiconductor device that emits a laser beam, and such a device is generally called an edge-emitting laser diode because laser light is emitted from the edge of a substrate. Typically, a diode laser with a single emitting area (emitter) is commonly referred to as a laser diode chip, while a linear array of emitters is referred to as a laser diode bar. The area where the laser beam is emitted is called a "face".

In the present invention, unless otherwise specifically stated, the terms "high power," laser and laser beam, and similar such terms, refer to and include laser beams and systems that provide or propagate laser beams having at least 100 watts (W) of power and greater powers, such as from 100W to 10 kilowatts (kW), from about 100W to about 1kW, from about 500W to about 5kW, from about 10kW to about 40kW, from about 5kW to about 100kW, and all powers within these ranges and greater powers.

In the present invention, unless specifically stated otherwise, the terms "blue laser beam," "blue laser beam," and "blue" shall have their broadest meaning and generally refer to a system that provides a laser beam, a laser source (e.g., a laser and a diode laser) that provides (e.g., propagates) a laser beam or light at a wavelength of from about 400nm to about 495nm, from 400nm to 495nm, and all wavelengths within these ranges. A typical blue laser has a wavelength in the range of about 405-495 nm. The blue laser includes wavelengths of 450nm, about 450nm, 460nm, about 460nm, 470nm, and about 470 nm. The blue laser may have a bandwidth from about 10pm (picometers) to about 10nm, about 5nm, about 10nm, and about 20nm and values greater and less.

In the present invention, unless specifically stated otherwise, the terms "green laser beam," "green laser," and "green" shall have their broadest meaning and generally refer to a system that provides a laser beam, laser source (e.g., lasers and diode lasers) that provides (e.g., propagates) a laser beam or light at a wavelength of from about 500nm to about 575nm. The green laser includes wavelengths of 515nm, about 515nm,532nm, about 532nm,550nm, and about 550 nm. The green laser may have a bandwidth from about 10pm to 10nm, about 5nm, about 10nm and about 20nm, and values greater and less.

In the present invention, unless specifically stated otherwise, the terms "high reliability", laser and laser system and similar terms refer to and include lifetimes of at least 10000 hours or more, about 20000 hours, about 50000 hours, about 100000 hours, from about 10 hours to about 100000 hours, from about 10000 hours to 20000 hours, from 10000 hours to 50000 hours, from 20000 hours to about 40000 hours, from about 30000 hours to about 100000 hours, and all values within these ranges, as well as larger values.

In the present invention, unless explicitly stated otherwise, the terms "lifetime", "system lifetime" and "extended lifetime" and similar terms are defined as the output power of the laser, other characteristics, and the time that both remain at or near their nominal values as a percentage ("nominal value", "nominal" and "nominal __", and similar terms refer to (i) the nominal power of the laser, other characteristics, and both, whichever is greater, as defined or calculated by the manufacturer, or (ii) the initial power of the laser, other characteristics, and both, whichever is greater, when first used after all calibration and adjustment is performed). Thus, for example, "80% laser life" is defined as the total operating time when the laser power, other characteristics, or both, are maintained at 80% or above the nominal value; i.e. the working time before the laser power, other characteristics or both is below 80% of the normal value. For example, "50% laser life" is defined as the total operating time when the laser power, other characteristics, or both remain at 50% or above the nominal value; i.e. the working time before the laser power, other characteristics or both is below 50% of the normal value.

In the present invention, the term "lifetime" (used without a numerical or percentage indicator) refers to and is defined as "80% laser lifetime" unless otherwise specified or clearly specified from the context.

In general, unless otherwise specified, the terms "about" and "to" as used herein are intended to encompass a variance or range of ± 10%, i.e., experimental or instrumental error, preferably the larger of those associated with obtaining the specified values.

In the present invention, unless otherwise expressly stated, the terms "at least", "greater than", and the like, also mean "not less than", i.e., such terms do not include lower values unless expressly stated otherwise.

In the present invention, the room temperature is 25 ℃, the standard temperature and pressure are 25 ℃ and 1 atmosphere unless otherwise specified. Unless otherwise expressly stated, all tests, test results, physical properties and values relating to temperature, pressure or both are provided at standard temperature and pressure.

In this disclosure, unless otherwise specified, numerical ranges (ranges from about "x" to about "y") and similar language and quantification are used merely as shorthand methods of referring individually to each separate value within the range. They include, therefore, each item, feature, value, quantity, or amount within the range. In the present invention, unless otherwise specified, each and every individual point within the range is incorporated into and a part of the specification as if they were individually recited herein.

Prior to the present invention, laser packages with multiple laser diodes, including multi-tube (multi-diode) laser diode packages, were subject to a combination of carbon and silicon contamination, which greatly reduced their lifetime and greatly increased the rate of degradation of their beam characteristics, including the rate of degradation of their power. It is common in the art to package the laser diodes individually to minimize contamination and achieve long lifetime. However, this prior approach has remained ineffective, unsuccessful and generally unsatisfactory in meeting the needs of current and further industrial laser applications and in using these diodes in laser systems (e.g., high brightness, high power systems). The disadvantages of this prior approach become more apparent and problematic as the demand for processing requirements and the demand for more laser diodes increase. Therefore, the problems of laser diode lifetime and beam quality degradation increase. This problem has existed and increased for laser diodes and diode systems in the ultraviolet, blue and green wavelengths.

The background of the invention section is intended to introduce various aspects of the art, which may be related to embodiments of the present invention. Therefore, the above discussion in this section provides a framework for better understanding the present invention and should not be taken as an admission of prior art.

Disclosure of Invention

There is a continuing need for more reliable high power blue, green, and other wavelength solid state lasers and systems, including laser diode systems for various applications such as welding, additive manufacturing, and other material processing. Therefore, in particular, there has been a long-standing and increasing demand for packaging a plurality of laser diodes into a single package and achieving a long life. There is a long-standing and increasing demand for longer-lived laser systems (including blue, green and other wavelengths), solid-state laser systems (including laser diodes and diode systems).

The present invention addresses these long-standing and growing needs by providing improvements, articles, devices, and processes, including those taught and disclosed herein.

Accordingly, a laser diode is provided that may be packaged in various configurations as shown in fig. 12-17. To achieve long life for these packaged laser diodes, the components and packaging are properly cleaned and assembled to eliminate silicone and carbon contamination prior to sealing the package. An oxygen-containing and preferably oxygen-rich environment is introduced into the package prior to sealing to remove any residual carbon contamination and convert it to CO ₂ Making it harmless to laser diodes.

Accordingly, there is provided a high power, high brightness solid state laser package for providing a high quality laser beam over a long period of time without significant degradation of the laser beam characteristics, said package having: a housing defining an internal cavity; wherein the internal cavity is isolated from an environment external to the housing; a solid state device for propagating a laser beam along a laser beam path from a propagation surface of the solid state device, wherein the laser beam has at least about 0.5MW/cm at the propagation surface ² The power density of (d); an optical assembly in optical communication with the solid state device and in the laser beam path(ii) a Wherein the solid state device and the optical assembly are located within the housing and in the internal cavity, whereby the solid state device and the optical assembly are isolated from an external environment; the housing includes a housing propagation surface, whereby the laser beam is transmitted from the housing into the external environment along the laser beam path; the housing propagation surface is in optical communication with the optical assembly and is in the laser beam path; the laser beam is characterized by beam characteristics upon exiting the housing propagation surface, the beam characteristics including: (i) a power of at least 100W; and (ii) a Beam Parameter Product (BPP) of less than 100mm mrad; and the inner cavity is free of silicon-based contamination sources, thereby avoiding SiO in the inner cavity during operation of the solid state device ₂ Generation of (2); whereby the inner cavity avoids SiO ₂ Accumulating; therefore, the degradation rate of the beam characteristics is 2.3% per khrs or less.

Further, there is provided a high power, high brightness solid state laser assembly for providing a high quality blue laser beam over a long period of time without significant degradation of the laser beam characteristics, said assembly having: a housing defining an internal cavity; wherein the internal cavity is isolated from an environment external to the housing; a plurality of diode laser devices for propagating a plurality of laser beams from a plurality of facets along a plurality of diode laser beam paths, wherein the laser beams have a wavelength in a range of 400nm to 500 nm; and wherein each laser beam has at least about 0.5MW/cm at each of said faces ² The power density of (d); an optical assembly in optical communication with each of the diode laser devices and in the laser beam path; the optical assembly includes collimating optics, such as collimating optics and beam combining optics; the optical assembly combines the plurality of diode laser beams to provide a combined laser beam along a combined laser beam path; wherein the plurality of diode laser devices and the optical assembly are located within the housing 526 and within the internal cavity, whereby the plurality of diode laser devices and optical assembly are isolated from an external environment; the housing includes a housing propagation surface, whereby the combined laser beam is transmitted from the housing into the external environment along the combined laser beam path; what is needed isThe housing propagation surface in optical communication with the optical assembly and on the combined laser beam path; the combined laser beam is characterized by beam characteristics upon exiting the housing propagation surface, the beam characteristics including: (i) a power of at least 100W; and (ii) a beam parameter product of less than 40mm mrad; and wherein said internal cavity is free of silicon-based contamination sources, whereby no SiO is generated within said internal cavity during operation of said plurality of diode laser devices ₂ (ii) a Whereby the inner cavity avoids SiO ₂ Accumulating; thus, the degradation rate of the combined beam characteristics is 2.3% per khrs or less.

Further, there is provided a high power, high brightness solid state laser assembly for providing a high quality blue laser beam along a laser beam path over a long period of time without significant degradation of the laser beam characteristics, the assembly having: a housing defining an internal cavity; wherein the inner cavity defines an isolation environment; a plurality of optically active surfaces, wherein the blue laser beam is transmitted from, transmitted into, or reflected by the optically active surfaces; the plurality of optically active surfaces are located within an isolated environment of the internal cavity of the housing; at least one of the optically active surfaces is located on a solid state laser device; wherein the laser beam has at least about 0.5MW/cm at one or more of the optically active surfaces ² And the cavity is free of silicon-based contamination sources, thereby avoiding the generation of SiO within the cavity during operation of the solid-state laser device ₂ (ii) a Wherein the inner cavity comprises an oxygen-containing gas; whereby during operation of the solid state laser device, CO is generated in the inner cavity from carbon based contamination ₂ (ii) a Whereby the multiple optically active surfaces avoid carbon and SiO ₂ (ii) accumulation of (d); therefore, the degradation rate of the power of the blue laser beam is 2.3% per khrs or less.

Further, there is provided a high power, high brightness solid state laser device package for integration into a laser system to provide a high quality blue laser beam over a long period of time without significant degradation of the laser beam characteristics, the package having: a housing defining an internal cavity; wherein the inner cavity is in communication with an environment external to the housingIsolating; the housing having a window, wherein the window defines a portion of the internal cavity; a solid state device for propagating a laser beam along a laser beam path from a propagation surface of the solid state device, wherein the laser beam has a wavelength in a range of 410nm to 500 nm; and wherein the laser beam has at least about 0.5MW/cm at the propagation face ² The power density of (a); the window is in optical communication with the solid state device and is in the laser beam path; wherein the solid state device is located within the housing and in the internal cavity, and wherein an inner surface of the window is not exposed to the external environment, whereby the solid state device and the inner surface of the window are isolated from the external environment; whereby the laser beam is transmitted along the laser beam path from the housing through the window into the external environment; the inner cavity is free of silicon-based contamination sources, thereby avoiding the generation of SiO in the inner cavity during operation of the solid state device ₂ (ii) a Whereby the inner cavity avoids SiO ₂ Accumulating; therefore, the degradation rate of the beam characteristics is 2.3% per khrs or less; and wherein the lumen has a gas containing at least 1% oxygen; whereby during operation of the plurality of diode laser devices, CO is generated in the internal cavity from carbon-based contamination ₂ So that the propagation surface and the inner surface of the window remain free of carbon build-up.

Further, systems and methods are provided having one or more of the following features: whereby no SiO is generated in the inner cavity during operation of the solid-state device ₂ (ii) a So that substantially no SiO is generated during operation of the solid-state laser ₂ So that the inner cavity does not contain SiO ₂ (ii) a Wherein during operation, the inner cavity remains SiO-free ₂ (ii) a Wherein the inner cavity is SiO-free ₂ (ii) a Whereby during operation of the solid state device no carbon deposits are produced within the internal cavity; whereby substantially no carbon deposits are generated during operation of the solid state laser such that the internal cavity is free of carbon deposits; wherein during operation, the inner cavity remains free of carbon deposits; wherein the lumen is free of carbon deposits; wherein the system has tens, hundreds, or thousands of laser diodes, wherein the system has a laser diode that emits a laser beam of a blue wavelength; wherein the system is provided withA laser diode emitting a laser beam having a wavelength of about 500nm and less; wherein the system has a laser diode that emits a laser beam having a wavelength from about 500nm to about 10 nm; wherein a beam parameter product of the laser beam is less than about 100mm mrad; wherein a beam parameter product of the laser beam is less than about 50mm mrad; wherein a beam parameter product of the laser beam is less than about 40mmmrad; wherein a beam parameter product of the laser beam is less than about 20mm mrad; wherein a beam parameter product of the laser beam is less than about 15mm mrad; wherein the system has a laser diode emitting a laser beam having a wavelength of from 500nm to 10 nm; wherein the laser beam has a bandwidth of about 20nm or less, about 5nm or less, about 1nm or less, about 0.5nm or less, from about 20nm to about 0.5nm, and all bandwidths in these ranges; wherein the laser system has focusing optics; wherein the laser system has collimating optics; wherein the laser system has a scanner; and wherein the laser system has a grating; wherein the laser system has a reflective optical element, wherein the laser system has a Volume Bragg Grating (VBG), a bragg grating, an etalon, a prism, a variable attenuator, a grating fiber, a graded index lens, a cylindrical lens, a wave plate, a polarization beam combiner cube, a monolithic optical beam combiner component, a raman crystal, a frequency doubling crystal, a dielectric mirror component, a beam sensor component, a power monitoring component; wherein the inner cavity has a gas with at least 10% oxygen, whereby during operation of the solid state device, CO is generated within the inner cavity from carbon-based contamination ₂ (ii) a Whereby the propagation surfaces of the optical component and the solid state device avoid carbon accumulation; and wherein the inner cavity has a gas containing at least 1% oxygen, whereby during operation of the solid state device, CO is produced within the inner cavity from carbon-based contamination ₂ (ii) a The propagation surfaces of the optical component and the solid-state device are thus protected from carbon build-up.

Further, there is provided a high power, high brightness solid state laser device package for integration into a laser system to provide a high quality blue laser beam over a long period of time without significant degradation of the laser beam characteristics, the package having: a housing definingAn inner cavity is formed; wherein the internal cavity is isolated from an environment external to the housing; the housing having a window, wherein the window defines a portion of the internal cavity; a solid state device for propagating a laser beam along a laser beam path from a propagation surface of the solid state device, wherein the laser beam has a wavelength in a range of 410nm to 500 nm; and wherein the laser beam has at least about 0.5MW/cm at the propagation face ² The power density of (a); the window is in optical communication with the solid state device and is in the laser beam path; wherein the solid state device is located within the housing and in the internal cavity, and wherein an inner surface of the window is not exposed to an external environment, whereby the solid state device and the inner surface of the window are isolated from the external environment; whereby the laser beam is transmitted from the housing through the window along the laser beam path to the external environment; the inner cavity is free of silicon-based contamination sources, thereby avoiding the generation of SiO in the inner cavity during operation of the solid state device ₂ (ii) a From this inner cavity SiO is avoided ₂ Accumulating; thus, the degradation rate of the beam characteristics is 2.3% per khrs or less; and wherein the lumen has a gas containing at least 1% oxygen; whereby during operation of the plurality of diode laser devices, CO is generated in the internal cavity from carbon-based contamination ₂ So that the propagation surface and the inner surface of the window remain free of carbon build-up.

Further, a sealed container is provided, which encloses a separate laser diode for providing a laser beam; the sealed container defines an interior cavity and an interior surface; wherein the inner surface is free of silicone contamination such that SiO is not formed during operation of the laser diode ₂ (ii) a And wherein said internal cavity contains means for preventing the formation of carbon contamination on said internal surface.

Further, a sealed container is provided, which encloses a plurality of individual laser diodes for providing laser beams; the sealed container defines an interior cavity and an interior surface; wherein the inner surface is substantially free of silicone contamination such that SiO is not formed during operation of the laser diode ₂ (ii) a And wherein said internal cavity contains means to prevent the formation of carbon contamination on said internal surface.

Further, a method of operating a sealed container enclosing individual laser diodes to propagate a laser beam having beam characteristics defining a nominal power and a nominal beam parameter product, wherein the sealed container includes a window and defines an interior cavity and an interior surface; the method comprises the following steps: propagating a laser beam from a face of a laser diode through the cavity and out of the window away from the sealed container for a total run time comprising at least 5000 hours; wherein no SiO is formed on the inner surface of the cavity during propagation of the laser diode ₂ (ii) a Wherein CO is formed within the internal cavity during propagation of the laser diode ₂ (ii) a And wherein during said runtime said laser beam retains at least 80% of its nominal power and at least 80% of its nominal beam parameter product, whereby said laser beam characteristics are minimally degraded during runtime.

Further, a method of operating a sealed container enclosing a plurality of individual laser diodes to propagate a combined laser beam having beam characteristics defining a nominal power and a nominal beam parameter product is provided, wherein the sealed container includes a window and defines an interior cavity and an interior surface; the method comprises the following steps: propagating the individual laser beams from the facet of the laser diode; combining the individual laser beams to form the combined laser beam within the cavity and directing the combined laser beam away from the window away from the sealed container for a total run time comprising at least 5000 hours; wherein no SiO is formed on the inner surface of the cavity during propagation of the laser diode ₂ (ii) a Wherein CO is formed within the internal cavity during propagation of the laser diode ₂ (ii) a And wherein during said runtime said combined laser beam retains at least 80% of its nominal power and at least 80% of its nominal beam parameter product, whereby said beam characteristics are minimally degraded during runtime.

Further, containers, packages, assemblies, and methods are provided having one or more of the following features: wherein the laser beam is a blue laser beam; wherein the laser beam is a green laser beam; wherein the laser beam has a power of 1W to 10000W, about 500WPower or about 1000W; wherein the laser beam has a beam parameter product from 50mm mrad to 10mm mrad, from 20mm mrad to 1mm mrad, or from 10mm mrad to 0.1mm mrad; wherein the laser beam has a power of from 0.5MW/cm ² To 1000MW/cm ² At least about 1MW/cm ² At least about 5MW/cm ² Or at least about 10MW/cm ² The power density of (d); wherein the means for preventing the formation of carbon contamination on the inner surface is an oxygen-containing atmosphere; wherein the oxygen-containing atmosphere has an oxygen concentration of at least 1%, at least 10%, at least 20%, at least 50%, or from 5% to 80%. Wherein the oxygen-containing atmosphere flows into and out of the sealed container; wherein the means for preventing the formation of carbon contamination on the inner surface is to render the inner surface free of carbon contamination; wherein the sealed container has an 80% laser life of at least 5000 hours; wherein the sealed container has an 80% laser life of at least 10000 hours; wherein the sealed container has an 80% laser life comprising 5000 hours to 10000 hours; wherein the rate of degradation is 2.5% per khrs or less; wherein the degradation rate is 2.0% per khrs or less; wherein the rate of degradation is 1.5% per khrs or less; having or using a heat sink on which the diode or diodes are mounted, thereby forming a two-dimensional array of laser diodes; having or using a backplane, wherein the diode or diodes are mounted on the backplane; comprising an optical element for manipulating the laser beam; wherein the container is or comprises a TO-9Can (resistor Outline-9 Can); wherein the diode laser is TO-9Can; wherein the power density of the laser beam is at least about 10MW/cm ² Said laser beam having a power of at least about 2W, said degradation rate being 2.0% per khrs or less; wherein the power density of the laser beam is at least about 5MW/cm ² Said laser beam having a power of at least about 1.5W, said degradation rate being 1.8% per khrs or less; wherein the power density of the laser beam is at least about 15MW/cm ² Said laser beam having a power of at least about 5W, said degradation rate being 2.3% per khrs or less; wherein the lumen has an atmosphere having at least 10% oxygen; wherein the lumen has an atmosphere having at least 40% oxygen; wherein the inner cavity toolHaving an atmosphere having at least 60% oxygen; wherein the silicon-based contamination source is selected from the group consisting of siloxanes, polymeric siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, and polysiloxanes; wherein the carbon-based contamination source is selected from the group consisting of solvent residue, oil, fingerprint, and hydrocarbon; wherein within the package or sealed container, the silicon contamination is less than 0.01g, less than 0.001g, less than 0.0001g, and less than 0.00001g, or less than 0.000001g; wherein within the package or sealed container, the silicon contamination is less than 0.01ppm (part per millionth) silicon, less than 0.001ppm silicon, less than 0.0001ppm silicon, or less than 0.00001ppm silicon; wherein the degradation rate of the beam characteristic is 2.0% per khrs or less; wherein the degradation rate of the beam characteristic is 1.8% per khrs or less; characterized by having a lifetime of not less than 10000 hours; characterized by having a lifetime of not less than 30000 hours; characterized by having a lifetime of not less than 50000 hours; characterized by having a lifetime of not less than 70000 hours; wherein the power density of the laser beam at the face, the window, or both is 0.5MW/cm ² To 1000MW/cm ² At least about 1MW/cm ² At least about 5MW/cm ² Or at least about 10MW/cm ² (ii) a Wherein the lumen comprises an atmosphere comprising at least 1% oxygen; wherein the run time comprises a total of at least 7500 hours; wherein the run time comprises a total of at least 10000 hours; wherein the 80% non-mail power is maintained for an additional 2500 hours of runtime; wherein the 80% non-mail power is maintained for an additional 5000 hours of runtime; and wherein operation occurs on a plurality of intermittent duty cycles, each duty cycle defining an operating duty cycle period, wherein the sum of the operating duty cycle periods is equal to the run time.

Drawings

Fig. 1 is a graph of output power versus time providing a degradation curve showing the degradation rate for a high power blue laser system.

Fig. 2 is a graph of an embodiment of improved power output versus time, providing a degradation curve showing the degradation rate for 4 different high power blue laser systems according to the present invention.

Fig. 3 is a schematic diagram of a laser system according to the present invention.

Fig. 4 is a schematic diagram of a laser system according to the present invention.

Fig. 5 is a schematic diagram of a laser system according to the present invention.

Fig. 6 is a schematic diagram of a laser system according to the present invention.

Fig. 7 is a graph of laser power in watts (percent) versus operating time (hours) for an embodiment of a laser system according to the present invention.

Fig. 8 is a graph of laser power (watts) versus on-time (hours) for an embodiment of a laser system according to the present invention.

Fig. 9 is a schematic diagram of a diode laser illustrating a typical area where contamination deposits may occur but are avoided by an embodiment of an extended lifetime laser according to the present invention.

Fig. 10 is a schematic diagram of a diode laser in a package providing extended lifetime in accordance with the present invention.

Fig. 11 is a schematic diagram of a laser diode bar in a package providing extended lifetime in accordance with the present invention.

Fig. 12 is a schematic cross-sectional view of one embodiment of a TO-9Can laser diode according TO the present invention.

Fig. 13 is a diagram of one embodiment of mounting the TO-9Can of fig. 12 in one embodiment of a multi-laser package in accordance with the present invention.

Fig. 14 is a diagram of one embodiment of mounting the TO-9Can of fig. 12 in one embodiment of a multi-laser package in accordance with the present invention.

Fig. 15A is a perspective view of one embodiment of a multi-diode laser package according to the present invention.

Fig. 15B is a plan view of the package of fig. 15A.

Fig. 15C is a cross-sectional view of the package of fig. 15A.

Fig. 16A is a schematic plan view of a multi-diode laser package according to the present invention. Is that

Fig. 16B is a cross-sectional view of the package of fig. 16A.

Fig. 17A is a schematic plan view of a multi-diode laser package according to the present invention. Is that

Fig. 17B is a cross-sectional view of the package of fig. 17A.

Detailed Description

The present invention relates generally to lasers that produce high quality and high reliability laser beams in the ultraviolet, blue and green wavelength ranges.

In embodiments, the present invention relates to lasers, laser packages and housings that produce high quality, high reliability and long life blue laser beams.

In an embodiment, a laser system and a solid state laser package for such a system are generally provided having a wavelength in the range of about 400nm to about 500nm with a lifetime of at least 5000 hours.

Although the present description focuses primarily on wavelengths of 500nm, this is illustrative only, and it should be understood that the packaging, assembly techniques and cleaning techniques provided are applicable to blue, cyan, green, shorter wavelength and potentially other wavelength laser systems, particularly high brightness, high power systems.

Typically, the output power of a blue laser diode emitter is typically about 5W per diode, typically less than 10W per diode, although higher powers are possible. A high power blue laser system is obtained by combining light beams from multiple emitters (e.g. diodes). The combination of these blue laser beams may come from a single emitter, emitter rod, and combinations and variations thereof. The laser beams from these emitters are combined using, for example, a combination of spatial, spectral, coherent, and polarization methods. Examples of these beam combining systems are taught and disclosed in U.S. patent publication nos. 2016/0322777, 2018/0375296, 2016/0067827, 2019/0273365, and 2020/0086388, and U.S. patent application serial No. 16/090695 filed 11, 25.2019, the entire disclosures of which are incorporated herein by reference.

Typically, the combination of these beams from multiple emitters involves the use of passive optical elements to collimate and combine the beams, such as lenses, mirrors, gratings, waveplates. Raman conversion can also be used for beam combining. Most industrial applications such as welding, brazing or additive manufacturing require high brightness light sources; they typically have a very short focal length lens placed near the laser emitter in the same package. Hereinafter, a component in a package refers to any element that forms a laser assembly; they are divided into optical functional components (e.g. lenses, gratings, mirrors, waveplates, windows), mechanical components (e.g. package housings, spacers, supports) and positioning components (e.g. adhesives, solders, mechanical hardware).

Laser diode manufacturers have made advances in the design and manufacture of blue laser diodes to ensure high reliability of the emitters themselves. In the same way, reliable dielectric coatings are available that provide the desired reflectivity at the blue wavelength while being compatible with the typical intensity of blue laser diode sources. However, prior to the present invention, high power blue laser diode systems lacked the level of reliability required for industrial applications, particularly cost-effectiveness for industrial applications. It has been found that this is due to the presence of silicon and carbon-based sources of contamination, which are typically introduced into the system during assembly of the system; and as discussed below, deposits form on the active optical surfaces of the system during laser operation, reducing laser performance and shortening the life of the laser and laser system.

It has been found that the limiting factor for the lifetime of a high power blue laser diode system and in embodiments the main limiting factor is related to the packaging of the system, in particular the diode, the optical component and the packaging of the diode and the optical component. Contamination of volatile organic compounds (e.g., hydrocarbons or silicones) can be caused by outgassing of adhesives or other materials in the package. Other common sources of contamination include air contamination present in the environment during assembly, residue from storage containers for any components, surface contamination present on tools used in the process, and any surfaces that are typically in contact with any materials used in packaging. In general, it is presently believed that any organic compound having a vapor pressure sufficient to produce trace gas contamination in the temperature range associated with proper laser operation may be detrimental to the reliability of the laser system. It is theorized that the short wavelength blue laser and the shorter wavelength laser allow two-photon processes to efficiently generate reactive species, such as atomic oxygen, hydroxyl radicals, or ozone, in the package. These reactive species then react with the volatile organic contaminants in the gas phase, causing deposits or various solids to accumulate on optical surfaces (i.e., optically active surfaces) in the beam path, increasing optical losses, reducing system output, and degrading the characteristics of the laser beam over time. It is theorized that these deposits and accumulations reduce and greatly reduce the life of the system. It is further theorized that these deposits and build-up are the primary cause of the end of the life of the system.

Thus, as described and taught in this specification, in embodiments of the present invention, it is theorized that these accumulations are minimized, reduced, and avoided, and that blue and potentially green laser systems are provided with high reliability, small degradation rates, and long lifetimes.

Referring to fig. 1, a plot of power output versus time for a typical blue laser system without reducing the amount of silicon contamination is shown. Thus, the system includes a silicon-based contamination source and is therefore not free of a silicon-based contamination source. P _i Is the initial power 101, which is also the nominal value, P _f Is the final power 102, which corresponds to 88.73% of the nominal value at an operating time of about 150 hours.

Comparing the poor performance of the system of fig. 1 with the performance of the embodiments of the present invention, as shown in fig. 2, shows a significant increase in laser lifetime using embodiments of the present invention. Fig. 2 shows four plots (lines) of power output versus operating time for four lasers 201, 202, 203, 204 in accordance with an embodiment of the present invention. At the 400 hour point, all of these lasers exhibited laser lifetimes greater than 98%.

Thus, referring to FIG. 3, FIG. 3 is a schematic block diagram of a high power, high brightness blue laser system 300. The system 300 has an array of laser diodes, such as emitters 301. The laser diode 301 has various mechanical features 320 for mounting, positioning and holding the diode. These mechanical components 320 are directly or indirectly physically associated with the base 321, e.g., connected to the base 321, attached to the base 321, etc. The base 321 is mechanically associated with a cover 322 having an inner surface 323. The cover 322 is connected to and sealed to a base 321 to form a housing 326, the housing 326 containing or containing an internal cavity 334 isolated from an external environment 335. There is an optical component 302 that is directly or indirectly physically associated with other mechanical components 324 that are directly or indirectly physically associated with the base 321. The laser diode 301 and optical component 302 are contained within the internal cavity 334 and are isolated from the external environment 335 by the housing 326.

Each laser diode has a facet, e.g., 304 (only one shown for clarity), from which the blue laser beam propagates. The laser beam 350 travels along a laser beam path 350a (it being understood that the laser beam travels along the laser beam path and thus coincides with the laser beam path) to the optical element 302 and then to and through the window 325 in the housing 326. Thus, the laser beam propagates through the internal cavity 334 and exits the cavity into the external environment 335.

The interior cavity of these embodiments, and therefore the environment within the cavity, and preferably all surfaces within the cavity, are free of silicon-based contamination sources, such as siloxanes, polymeric siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, and polysiloxanes. In particular, in one embodiment, the surfaces and joints within the housing that are heated during operation, exposed to the laser beam, and preferably both, are free of silicon-based contamination sources. By "free" is meant that the amount of contamination present is very low, such that the amount of silicon (or designated contamination) released into the internal cavity during operation is minimal, preferably zero. In this manner, it is theorized that the reactive oxygen species formed during propagation of the blue laser beam through the internal cavity are substantially free of silicon and have no silicon reactive therewith, thereby minimizing SiO ₂ Preferably SiO is avoided ₂ More preferably no formation of SiO ₂ And, in turn, minimizing SiO ₂ Deposit, avoidance of SiO ₂ Deposits, and more preferably does not have SiO on the optically active surface within the cavity ₂ And (4) forming a deposit. The amount of silicon-based contamination is avoided and thus reduced to such a low level that it is useful for forming SiO ₂ Any of the usable silicon ofIs minimal, negligible, or below a level that causes a laser degradation rate greater than embodiments of the present system. In general, an optically active surface is any surface that is in contact with the laser beam and in the path of the laser beam, which would include facets, fiber facets, mirrors, lenses, windows, propagation facets, and transmission surfaces.

However, the lumen of these embodiments, as well as the environment within the lumen, may contain sources of carbon-based contamination. Thus, all or most of the carbon-based contamination need not be cleaned during assembly (e.g., packaging) of the laser assembly or system. The carbon-based contaminants include, for example, detergents, solvents, lubricants, oils, human fingerprints and oils, and generally any other hydrocarbon source. The interior chamber contains gaseous oxygen, a source of gaseous oxygen during operation (e.g., a port or flow line in the housing that supplies oxygen to the system during operation), or both. When exposed to a blue laser beam, the oxygen forms reactive atomic oxygen, which forms gaseous CO by reacting with any carbon released by the carbon-based contamination source ₂ Thus, deposition, deposit or accumulation of carbon on optically active surfaces within the lumen is minimized, preferably avoided and more preferably prevented.

The lumen of these various embodiments may contain from 1% to 100%, from about 5% to about 80%, from about 10% to about 50%, from about 30% to about 80%, from about 5% to about 30%, and the ambient amount of oxygen present in the air (e.g., the lumen may contain clean, dry air). The other gas in the lumen may be nitrogen.

The lumens of these embodiments may have less than 0.01ppm silicon, less than 0.001ppm silicon, and less than 0.0001ppm silicon, as well as lesser amounts present in or available for the lumens.

The blue laser beam of the laser assembly, in combination with one (and preferably both) of gaseous oxygen in the cavity and the absence of silicon-based contamination sources in the cavity, can provide an assembly having a lifetime (and can also be accurately characterized, sold, and labeled as having the lifetime) of from about 5000 hours to about 100000 hours, from about 10000 hours to about 90000 hours, from about 5000 hours to about 50000 hours, from about 30000 hours to about 70000 hours, at least about 20000 hours, at least about 30000 hours, at least about 40000 hours, at least about 50000 hours, and longer.

These various embodiments of laser systems or assemblies having these high reliabilities (i.e., these long lifetimes) may provide or propagate a blue laser beam (e.g., wavelengths from about 410nm to about 500nm, from 410nm to 500nm, about 405-495nm, 450nm, about 450nm, 460nm, about 460nm, 470nm, and about 470 nm). The blue laser beams may have bandwidths of from about 10pm (picometers) to about 10nm, about 5nm, about 10nm, about 20nm, from about 10nm to about 30nm, from about 5nm to about 40nm, about 20nm or less, about 30nm or less, about 15nm or less, about 10nm or less, and greater and lesser values. The blue laser beams may have a power of from about 100W (watts) to about 100000W, from about 100W to about 40000W, from about 100W to about 1000W, about 200W, about 250W, about 500W, about 1000W, about 10000W, at least about 100W, at least about 200W, at least about 500W, at least about 1000W, and greater and lesser. For individual diode packages, the laser beams may have a power of from about 1W to about 10W, about 3W, about 5W, about 6W, about 10W, and greater. These blue laser beams can have a beam parameter product from about 5mmmrad to about 50 mmrad, less than about 40 mmrad, less than about 30 mmrad, less than about 20mmmrad, less than about 15 mmrad, less than about 10 mmrad, 20mm mrad and lower, 15mmmrad and lower, and greater and lesser values. For Raman laser based systems, the beam parameter product of these blue laser beams can be less than 5mm mrad, less than 1mm mrad, from about 0.1 to about 0.5mm mrad, about 0.13mm mrad, and about 0.15mm mrad.

The degradation rate of the beam characteristics (e.g., power, BBP, bandwidth, or other characteristics of the beam, and combinations of one or more and all of these characteristics) of the laser beams for these various embodiments of laser systems and assemblies can be about 2.5% per khrs (1000 hours) or less, about 2.3% per khrs or less, about 2.1% per khrs or less, about 2.0% per khrs or less, about 1.8% per khrs or less, from about 2.3% per khrs to about 1.5% per khrs, and greater and lesser amounts. In a preferred embodiment, these degradation rates are based on "normal values" of the laser characteristics, starting from "normal values" of the laser characteristics, during the lifetime of the laser system, and both. In a preferred embodiment, these degradation rates exist throughout the life of the system. In a more preferred embodiment, the laser system will have its life cycle when the degradation curve (i.e., the degradation versus time plot) is flat (i.e., the degradation rate is zero). The zero degradation period may be from 1 hour to 500 hours or more, may be 10% of the lifetime, 20% of the lifetime, 30% of the lifetime or more.

It should be noted that these contaminations (silicon-based and carbon-based) form when the laser is operated at lower power and also at high power over its entire operating range and power rating. Thus, unless explicitly stated otherwise, these degradation rates are used for operation of the laser at rated power, within a rated operating range, or under normal conditions, and establish an operating range for such lasers.

It is theorized that there are two main components that contribute to the accumulation of deposits on the optically active surface, thereby reducing the lifetime of the blue laser system. These components are carbon and SiO ₂ . It is conventionally thought that any component that contributes to such deposits should be reduced or eliminated during assembly and packaging. However, the present invention departs from these conventions, increasing the amount of oxygen will potentially increase SiO ₂ In order to manage any residual hydrocarbon contamination. In this way, there may be residual hydrocarbon contamination, but due to the elevated oxygen levels, the system avoids and preferably does not pose a risk to the system. The amount of siloxane is minimized and preferably eliminated. Thus, siO ₂ One of the components required for deposits or build-up is minimized or eliminated; enabling oxygen to pass through to form CO ₂ Rather than solid carbon build-up or deposited material to neutralize hydrocarbon build-up and deposits. In an embodiment, the amount of hydrocarbon contamination is preferably minimized and may be substantially eliminated.

A number of different cleaning and assembly techniques and procedures are known, such as clean room assembly and protocols, solvent cleaning, extraction, plasma cleaning, etc., which can be used to remove and avoid the presence of any silicon-based contamination source, any carbon-based contamination source, and both. The cleaning and assembly techniques of the present invention are examples of many different such techniques and combinations of such techniques, which may be applicable to these laser systems; and will be suitable for blue laser systems, shorter wavelength systems, blue-green and green laser systems, and the high power system of this embodiment. In embodiments of the present solid state laser, optical assembly, laser system, and combinations and variations thereof, assembly processes, various methods of cleaning and assembling the components may be used to minimize the adverse effects of various contamination phenomena that have been found for blue and green laser systems, as well as for shorter wavelength systems. In an embodiment, methods of cleaning and assembling optical components of blue laser systems and systems having lower and higher wavelengths are used to mitigate, minimize or eliminate materials that degrade laser performance over time. These assembly processes for such lasers, optical assemblies and systems address the reliability shortcomings of existing systems. For example, in one embodiment, a cleaning method is used to remove silicon-based contamination sources, and the working method in an embodiment is configured to remove target contamination at specific steps in the assembly process, at specific locations on the component, and at combinations and variations of these. The cleaning method may provide an embodiment of a package that houses a solid state laser, an optical component, a laser system (e.g., a laser and an optical element), or a combination thereof, preferably with a silicon-based contamination level that is undetectable by standard analytical techniques. Such packages, including any of the present embodiments and examples, may have an amount of silicon-based contamination of less than 0.01g, less than 0.001g, less than 0.0001g, less than 0.00001g, and less than 0.000001g in the isolated environment of the package. Such packages, including any of the present embodiments and examples, may have an amount of silicon-based contamination (determined by ppm silicon based on the composition of the interior chamber environment) in the interior chamber of less than 0.1ppm silicon, less than 0.01ppm silicon, less than 0.001ppm silicon, or less than 0.0001ppm, less than 0.00001ppm silicon and lower. These systems and methods may have one or more of the following features: wherein volatile contamination of the polysiloxane is primarily removed; wherein the benefits of removing any residual volatile hydrocarbons are provided; and wherein other operating parameters are selected to clean up different contamination.

In an embodiment of the assembly process, plasma cleaning, in particular plasma cleaning, is used to remove trace contamination from the surface of the component in the package to remove contamination or particles, e.g. a larger amount of such contamination or particles. In one embodiment, plasma cleaning is used with a pre-cleaning step, where the surface is pre-cleaned using carefully selected polar and non-polar solvents. Preferably, the solvent is selected so that its polarity matches that of the target contamination. Thus, it is envisioned that multiple pre-cleaning, and plasma cleaning steps may be performed, and that these steps may be tailored to specific contamination.

In one embodiment of these assembly processes, the system components are heated at a contrasting pressure for a predetermined time to remove residual traces of volatile contamination to accelerate the venting of all volatile components. This preheating step can be, and preferably is, used with the other assembly techniques disclosed in this specification. The operating conditions of temperature and pressure are chosen so that the vapor pressure of the targeted contamination is higher than the actual pressure in the oven, while still being safe for the part. This step also ensures that any solvent residue from the pre-cleaning step is removed from the component.

An embodiment of the assembly process defines a sequence of pre-cleaning and cleaning, wherein it is advantageous to measure the polar and non-polar components of the surface free energy of the part to be cleaned at different stages of the cleaning process. This provides useful information to select the appropriate combination of solvent and optimal gas mixture to target the actual contamination to be removed. In an embodiment, the order of preference may be different for different components of the assembly due to different histories of manufacturing, storing, and processing of each part.

In one embodiment of the assembly process, these cleaning techniques are performed as an additional or second or third cleaning step (e.g., a final cleaning step) prior to or at the time of packaging. It is recognized that even if parts and tools are carefully cleaned before assembly occurs, some contamination may be introduced into the package during integration. This may result, for example, from air pollution present in the assembly area; outgassing of the adhesive during curing is another source of contamination. Thus, in one embodiment, final cleaning of the assembly is performed just prior to sealing the package. The same cleaning methods described in this invention for the individual components can be used.

Referring to fig. 9, a schematic diagram of a laser diode 1000 is shown. The diode has a lateral guiding ridge 1010, a front face 1011, a mode 1012, and a vertical confinement layer 1013. The contamination formed during operation generally accumulates along the laser diode vertical confinement layer 1013, with the largest contamination being deposited in the central region of the mode and typically decreasing with mode intensity in the lateral direction. Embodiments of the present system and method provide a system that avoids, minimizes, and preferably prevents such accumulation and other accumulation and deposits from occurring when in operation.

To prevent the ingress of external contaminants, high power laser systems are typically sealed with an inert or protective atmosphere, e.g., an atmosphere with little and preferably no oxygen. However, this technique has proven to be less effective for blue laser systems and is not effective for providing long-lived blue laser systems. It is theorized that the previous use of an inert atmosphere was not effective for the blue laser system and not for the green laser system due to the contamination dissociation effects discussed in this specification. It is theorized that the potential other phenomena are both understood and incompletely understood, but that during normal operation of these blue wavelength laser systems, as well as in green laser systems, it can be seen who has an effect on the degradation of laser performance. Further, during operation of these systems, the temperature inside the package increases, which also results in venting of any components in the assembly; thus, these trace contaminants from the hot exhaust gas can have an adverse effect on the reliability of the system, and in some cases, the effect can be very adverse.

Embodiments of the present invention have discovered these problems with blue wavelength systems and it is theorized that the green laser system and the shorter wavelength system, among other things, provide examples of suitable methods for precisely cleaning, assembling, and cleaning and assembling the package or housing of the system, including the optical package (and the components within the package, including the solid state laser) during assembly, and preventing these adverse processes and degradation of the laser system from occurring.

In addition to volatile organic contamination build-up on optical surfaces in the beam path, another problem is silicon dioxide (SiO) on the surface of the laser diode facet or other optical component ₂ ) Is accumulated. This accumulation of silica results in a change in the reflectivity of the coating. In some cases, the accumulation of silica changes the optical properties of the surface. Before collimation, a single blue laser diode has a very strong optical field at the surface of the laser diode itself. The power density at the face may exceed 20MW/cm due to modal filaments formed in the cavity ² A peak value. It has been found and theorized that this high power density is responsible for driving the two-photon reaction that dissociates the atmosphere in the package. Once dissociated, the free oxygen atoms rapidly combine with any free silicon to form SiO at the face ₂ . The SiO ₂ Deposited in a manner similar to carbon gettering. Formation and deposition of SiO ₂ May also be performed in other optical elements including collimating optics, but may be in the order of several kW/cm due to the much lower power density at the collimating optics ² The deposition rate is 1000 times less than at the face, but should still be considered in the packaging, assembly and cleaning of the system.

The laser beam propagates from an optically active surface of a solid state laser device of the present systems and assemblies, such as a fiber facet, window, or facet, which may have at least about 0.5MW/cm ² At least about 1MW/cm ² (megawatts per square centimeter) of at least about 10MW/cm ² At least about 20MW/cm ² At least about 50MW/cm ² At least about 100MW/cm ² At least about 500MW/cm ² About 1000MW/cm ² Or less, from about 10MW/cm ² To about 100MW/cm ² From about 5MW/cm ^{2 to} About 20MW/cm ² And from about 50MW/cm ² To about 500MW/cm ² 。

Any solid state device for generating and propagating a laser beam may be used in the present system and assembly. Preferably, the solid state device transmits a laser beam having blue, cyan and green wavelengths. Such solid state lasersThe optical devices may be, for example, laser diodes, fiber lasers, raman fiber lasers, and crystal-based (e.g., diamond, KGW [ potassium gadolinium tungstate)]、YVO ₄ [ Yttrium Vanadate ]]、Ba(NO ₃ ) ₂ [ barium nitrate]Etc.), and combinations and variations of one or more thereof. The system may have one, two, three, five, ten, tens, hundreds, and thousands of such solid state devices whose beams are combined to provide a high power, high brightness laser beam for industrial and other applications.

It is to be understood that while the present description focuses on a complete laser system, such as a solid state laser device and optical assembly combined or integrated into one package or housing, the teachings are equally applicable to a stand-alone laser device without optical elements, a stand-alone optical assembly without lasers, and combinations and variations thereof. These components may be optically integrated, for example, by being connected by optical fibers with optical connectors in the field or prior to shipment.

Embodiments of the present laser apparatus and system may be used in industrial applications, such as for welding components, including components in electronic storage devices.

This process occurs whether the device is pulsed or continuous wave operation, since the process of creating deposits on the facets and other surfaces of the laser diode and other optically active surfaces results in power losses that are driven by two-photon processes. The difference between the two modes of operation is SiO ₂ Deposition rate on the laser diode facet. The deposition rate is proportional to the power density and the deposition amount is the integral of the deposition rate over time. Thus, if the deposition rate is 10 μm per 1000 hours when operating with continuous wave, the deposition rate is only 1 μm per 1000 hours when operating at a 10% duty cycle. The deposition rate used here is merely an example and depends on many other factors, mainly the amount of polysiloxane trapped in the package.

The comparative examples given in fig. 1 and 2 use a 60W class blue laser consisting of 20 individual emitting diodes, each collimated by a fast axis collimating lens to allow coupling into a transmission fiber. After sub-micron precision alignment, the lens is attached to the ultraviolet cured optical epoxy. The package is made of gold plated copper pieces using low temperature solder. The lens is attached to a glass mount to match the coefficient of thermal expansion. This fairly simple assembly used 3 different types of optical adhesives, 2 solders, 3 different glasses, and 2 different gold-plated copper. The assembly process involves multiple steps, using different tools and component storage containers, all of which have the opportunity to contaminate the surface. Thus, the interaction of blue light with contamination can cause rapid degradation of the device output power over time. This is illustrated in fig. 1, which shows the performance of a typical device in an extension test; the life expectancy of the laser is only around 200 hours (defined in terms of time to reach 80% of nominal power), clearly insufficient for industrial work. The graph of fig. 1 shows a very typical degradation rate-100%/khrs, with a corresponding lifetime of the device of less than 200 hours. The devices in fig. 1 and 2 have the same amount of oxygen, i.e. 60%.

It has been found that there are at least two blue light interactions in the system that are detrimental to laser performance, particularly over time. First, scattered light from the system, reflected light, and both heat the surfaces of the system, increasing the outgassing of these surfaces, increasing the amount of volatile contamination, which in turn increases the amount of contamination deposited thereon and degrades the performance of the laser system. Second, the laser beam photolyzes oxygen via a two-photon process. The oxygen atoms then react with the organic matter in the package to form CO ₂ And reacted with polysiloxanes to form SiO ₂ . In the case of organic substances, CO ₂ Do not deposit on any surface and therefore their hydrocarbon source is of less interest, but silicone is very detrimental to reliability. Accordingly, the packaging environment (e.g., the internal environment of the housing containing the solid state laser device, the beam path, and the optical elements) is assembled and sealed to prevent the introduction of moisture and other contaminants for reliable operation.

Fig. 2 shows a graph of the output power variation from 5 samples of high power blue laser devices packaged and assembled in an internal environment free of siloxane and in an oxygen atmosphere. The laser apparatus used for the fig. 2 test was cleaned using an example of a cleaning sequence according to the present embodiment. The average degradation rate of these devices was-2.3% per khrs, which is a 43-fold improvement in lifetime compared to the device in fig. 1 without siloxane.

The following examples are presented to illustrate various embodiments of the present assembly method, laser system and operation. These examples are for illustrative purposes and are envisioned and should not be construed as limiting the scope of the invention in any way.

Example 1

Referring to fig. 10, a schematic diagram of the laser diode of fig. 9 assembled into a sealed package to extend the life of the diode is shown. The package may then be integrated into a laser system, providing an extended lifetime for the system. The diode 1000 is located inside a sealed housing 1050, which forms the package for the laser diode or packages for the laser diode and is a laser diode assembly. The housing 1050 contains an internal environment 1051 that is isolated from an external environment 1052. Diode 1000 propagates a laser beam along laser beam path 1056, through window 1055, and into external environment 1052. An inner surface 1080 of window 1055 is exposed to internal environment 1051 and is in contact with internal environment 1051. All surfaces in the internal cavity are free of silicon-based contamination. The laser beam has a power of 3W in the blue wavelength range. The internal environment contains 60% oxygen, whereby during operation of the solid state device, CO is generated in the internal cavity from any carbon based contamination that may be present after cleaning ₂ . The package assembly has a power degradation rate of less than 2.0% per khrs and a laser lifetime of at least 30000 hours.

Example 1A

In the example 1 embodiment, the internal environment may contain from 1% to 80% oxygen. The laser beam power may be from about 1W to about 10W, and the power degradation rate may be less than 3% per khrs, less than 2.5% per khrs, less than 2% per khrs, and less than 1.5% per khrs. The embodiments can have a laser lifetime of at least 20000 hours, at least 40000 hours, at least 50000 hours, and at least 100000 hours. In particular, the embodiments may have these lifetimes and degradation rates when assembled into a laser system (e.g., packaged with optical elements).

Example 1B

The laser diode of example 1 is a TO-9Can blue laser diode, an embodiment of which is shown in FIG. 12.

Example 1C

Referring to fig. 11, a schematic diagram of four laser diodes providing a blue laser beam, assembled into a hermetic package to extend the lifetime of the diodes is shown. The package may then be integrated into a laser system, providing an extended lifetime for the system. The four laser diodes 1100a, 1100b, 1100c, 1100d are encapsulated (e.g., contained) within a housing 1150, the housing 1150 being sealed and thus having an internal environment 1151. The housing 1150 protects and isolates an internal environment 1151 from an external environment 1152. The four laser diodes propagate blue laser beams of about 5W power that travel along beam paths 1156a, 1156b, 1156c, 1156 d. The laser beams travel along respective beam paths, exit housing 1150 through window 1155, and travel there into external environment 1152. An inner surface 1180 of the window 1155 is exposed to and in contact with the internal environment 1151. Four separate windows, one for each diode, may also be used. All surfaces in the internal cavity are free of silicon-based contamination. The laser beams are all in the blue wavelength range and each have a power of about 5W. The internal environment contains 60% oxygen, so during operation of the solid state device, any carbon based contamination remaining after cleaning generates CO within the internal cavity ₂ . The power degradation rate of the packaging assembly is lower than 2.0%, and the laser life is at least 30000 hours.

Example 1D

In the example 1C embodiment, the internal environment may contain from 1% to 80% oxygen. The laser beam power may be from about 1W to about 10W, and the power degradation rate may be less than 3% per khrs, less than 2.5% per khrs, less than 2% per khrs, and less than 1.5% per khrs. The embodiments can have a laser lifetime of at least 20000 hours, at least 40000 hours, at least 50000 hours, and at least 100000 hours. In particular, the embodiments may have these lifetimes and degradation rates when assembled into a laser system (e.g., packaged with optical elements).

Example 1E

The laser diode of example 1C is a TO-9Can blue laser diode, an embodiment of which is shown in FIG. 12.

Example 2

Referring to fig. 4, there is shown a schematic diagram of an embodiment of a high power, high brightness solid state laser assembly 400 or laser system for providing a high quality laser beam 450 over a long period of time without significant degradation of the laser beam characteristics, the assembly having: a housing 426 defining an internal cavity 434; wherein the interior cavity is isolated from an environment 435 external to the housing; a solid state device 401 for propagating a laser beam 450 along a laser beam path 450a from a propagation surface 404 of the solid state device, wherein the laser beam has at least about 0.5MW/cm at the propagation surface 404 ² The power density of (d); an optical component 402 in optical communication with the solid state device 401 and on the laser beam path 450 a; wherein the solid state device and the optical assembly are located within the housing 426 and within the internal cavity 434, whereby the solid state device and the optical assembly are isolated from the external environment 435; the housing includes a housing propagation surface 425 whereby the laser beam 450 is transmitted from the housing 426 along a laser beam path 450a into an external environment 435; the housing propagation surface 425 is in optical communication with the optical assembly 402 and on the laser beam path 450 a; the laser beam is characterized by beam characteristics upon exiting the housing propagation surface, the beam characteristics including: (i) a power of at least 100W; and (ii) a beam parameter product of less than 40mm mrad; and, the internal cavity is free of silicon-based contamination sources, whereby SiO is not generated within the internal cavity during operation of the solid state device ₂ (ii) a Thereby the inner cavity is kept free of SiO ₂ Accumulating; therefore, the degradation rate of the beam characteristics is 2.3% per khrs or less.

Example 3

In an embodiment, the laser assembly of example 2 has a solid state device that generates a laser beam, wherein the laser beam has a wavelength in a range of 410nm to 500 nm.

Example 4

In an embodiment, the laser assembly of example 2 has a solid state device that generates a laser beam, wherein the laser beam has a wavelength in a range of 405nm to 575nm.

Example 5

In an embodiment, the laser assembly of example 2 has a solid state device that generates a laser beam, wherein the laser beam has a wavelength in a range of 500nm to 575nm.

Example 6

In embodiments of the laser assemblies of examples 2, 3, 4, and 5, the solid state device is a raman fiber laser, a diode laser, a crystal-based raman laser, and combinations and variations of one or more thereof. The optical assembly has optical elements including collimating optics, focusing optics, lenses, mirrors, beam combining optics, and combinations and variations of one or more thereof. The beam characteristics also have a bandwidth of about 20nm or less. The housing propagation surfaces are windows and fiber surfaces, and combinations and variations of one or more thereof. A beam parameter product of less than about 15mm mrad; and, the power density at the propagation surface is from about 1MW/cm ² To about 1000MW/cm ² 。

Example 7

In the embodiments of the laser assemblies of examples 2, 3, 4, 5, and 6, the power of the laser beam is from about 100W to about 1000W. The beam characteristics further include a bandwidth of about 20nm or less; the power density at the propagation surface is from about 0.5MW/cm ² To about 1000MW/cm ² (ii) a And, the degradation rate of the beam characteristics is less than 2.0% per khrs.

Example 8

In the embodiments of the laser assemblies of examples 2-7 and 13-26, the inner cavity includes a gas containing at least 1% oxygen; whereby CO is produced from carbon-based contamination in the internal cavity during operation of the solid state device ₂ (ii) a Whereby the propagation surfaces of the optical component and the solid-state device remain free of carbon build-up.

Example 9

In the embodiments of the laser assemblies of examples 2-7 and 13-26, the inner cavity includes a gas containing at least 5% oxygen; whereby CO is produced from carbon-based contamination in the internal cavity during operation of the solid state device ₂ (ii) a Whereby the optical assembly and the solid-state device have a propagation surfaceWith no carbon build-up.

Example 10

In the embodiments of the laser assemblies of examples 2-7 and 13-26, the inner cavity includes a gas containing at least 10% oxygen; whereby CO is produced from carbon-based contamination in the internal cavity during operation of the solid state device ₂ (ii) a Whereby the propagation surfaces of the optical component and the solid-state device remain free of carbon build-up.

Example 11

In the embodiments of the laser assemblies of examples 2-7 and 13-26, the inner cavity includes a gas containing at least 20% oxygen; whereby CO is produced from carbon-based contamination in the internal cavity during operation of the solid state device ₂ (ii) a Whereby the propagation surfaces of the optical component and the solid-state device remain free of carbon build-up.

Example 12

In the embodiments of the laser assemblies of examples 2-7 and 13-26, the inner cavity comprises a gas comprising from about 5% to at least about 50% oxygen; whereby CO is produced from carbon-based contamination in the internal cavity during operation of the solid state device ₂ (ii) a The propagation surfaces of the optical components and the solid-state device are thereby kept free from carbon build-up.

Example 13

In the embodiments of the laser assemblies of examples 2-12 and 17-26, the degradation rate of the beam characteristics was 2.0% per khrs or less, from 2.0% to 1% per khrs.

Example 13A

The degradation rate of example 13 maintained 5000 hours of life, 7000 hours of life and 10000 hours of life.

Example 14

In the embodiments of the laser modules of examples 2 to 12 and 17 to 26, the degradation rate of the beam characteristics was 1.8% per khrs or less, from 1.8% to 0.8% per khrs.

Example 14A

The degradation rate of example 14 maintained 5000 hours of life, 7000 hours of life and 10000 hours of life.

Example 15

In the embodiments of the laser assemblies of examples 2-12 and 17-26, the assemblies have and are characterized by an extended lifetime of not less than 10000 hours.

Example 16

In the embodiments of the laser assemblies of examples 2-12 and 17-26, the assemblies were characterized as having an extended lifetime of not less than 5000 hours.

Example 17

Referring to fig. 5, a schematic diagram of a high power, high brightness solid state laser assembly 500 is provided for providing a high quality blue laser beam 550 over a long period of time without significant degradation of the laser beam characteristics, the assembly having: a housing 526 defining an internal cavity 534; wherein the interior cavity is isolated from an environment 535 external to the housing 526; a plurality of diode laser devices 501a, 501b, 501c, 501d, 501e for propagating a plurality of laser beams (e.g., beam 550) from a plurality of facets (e.g., facet 504) along a plurality of diode laser beam paths (e.g., path 550 a), wherein the laser beams have wavelengths in the range of 400nm to 500 nm; and wherein each laser beam has at least about 0.5MW/cm at each of said faces ² The power density of (d); an optical assembly 502 in optical communication with each of the diode laser devices and in the laser beam path; the optical assembly includes collimating optics, such as collimating optics 560 and beam combining optics 565; optical assembly 502 combines the plurality of diode laser beams to provide a combined laser beam 552 along a combined laser beam path 552 a; wherein a plurality of diode laser devices and the optical assembly are located within the housing 526 and within the interior cavity 534, whereby the plurality of diode laser devices and the optical assembly are isolated from an external environment 535; the housing includes a housing propagation surface 525 whereby the combined laser beam is transmitted from housing 526 along combined laser beam path 552a into external environment 535; housing propagation surface 525 is in optical communication with optical assembly 502 and is on combined laser beam path 552 a; combined laser beam 552, upon exiting housing propagation surface 525, is characterized by beam characteristics including: (i) a power of at least 100W; and (ii) a beam parameter product of less than 40mm mrad; also, the cavity 534 is free of silicon-based contamination sources, such that during operation of the multiple diode laser apparatus, no SiO is generated in the cavity ₂ (ii) a Whereby the inner cavity remains SiO-free ₂ Accumulating; thus, the degradation ratio of the combined beam characteristic is 2.3% per khrs or less.

Example 18

In an embodiment of the laser assembly of example 17 and other examples, the beam characteristics further include a bandwidth of about 15nm or less; the housing propagation surface is selected from the group consisting of a window and a fiber surface; a beam parameter product of less than about 15mm mrad; and the power density at the propagation surface is from about 0.5MW/cm ² To about 1000MW/cm ² 。

Example 19

In an embodiment of the laser assembly of example 17 and other examples, the beam characteristics further include a bandwidth of about 15nm or less; the power of the combined laser beam is at least about 500W; the housing propagation surface is selected from the group consisting of a window and a fiber surface; a beam parameter product of less than about 30mm mrad; and the power density at the propagation surface is from about 0.5MW/cm ² To about 1000MW/cm ² 。

Example 20

Referring to fig. 6, a schematic diagram of a high power, high brightness solid state laser assembly 600 is provided for providing a high quality blue laser beam 650 along a laser beam path 650a over a long period of time without significant degradation of the laser beam characteristics, the assembly having: a housing 626 defining an internal cavity 634; wherein the interior cavity 634 defines an isolation environment; a plurality of optically active surfaces, e.g., surface 604a, surface 604b, surface 604c, surface 604d, surface 604e, wherein a blue laser beam is transmitted from, transmitted into, or reflected by the optically active surfaces; a plurality of optically active surfaces are located within an isolated environment of the interior cavity 634 of the housing; at least one optically active surface is located on the solid state laser device 601; wherein the laser beam has at least about 0.5MW/cm at one or more of the optically active surfaces ² Such as surface 604a, surface 604b, surface 604c, surface 604d, surface 605e; also, the cavity 634 is free of silicon-based contamination sources, thereby not creating SiO within the cavity during operation of the solid-state laser device ₂ (ii) a Wherein the interior cavity 634 includes a gas comprising oxygen; whereby during operation of said solid state laser device, the cavity isCO production from carbon-based pollution ₂ (ii) a Whereby the plurality of optically active surfaces remain free of carbon and SiO ₂ Accumulating; therefore, the degradation rate of the power of the blue laser beam is 2.3% per khrs or less.

Optically active surface 604e is a window for transmitting laser beam 650 out of the housing and into external environment 635.

Example 21

The laser assembly 600 of fig. 6 and the laser assembly 500 of fig. 5, wherein the solid state laser generates a laser beam having a wavelength in the green wavelength range.

Example 21A

The green solid-state laser of example 22 is an infrared laser system that doubles in a lithium niobate crystal. The system may have a laser diode, an external cavity, and a lithium niobate crystal located at the focal point of the external cavity, all contained within the housing.

Example 22

The laser systems and components of examples 2-21, 21A, wherein the laser beam has a bandwidth of about 5nm, about 10nm, about 20nm, from about 10nm to about 30nm, from about 5nm to about 40nm, about 20nm or less, about 30nm or less, about 15nm or less, about 10nm or less.

Example 23

The laser systems and assemblies of examples 2-22, wherein the laser beam at or near a point where the beam exits the housing and propagates into the external environment has a power of from about 100W to about 100000W, from about 100W to about 40000W, from about 100W to about 1000W, about 200W, about 250W, about 500W, about 1000W, about 10000W, at least about 100W, at least about 200W, at least about 500W, and at least about 1000W.

Example 24

The laser systems and assemblies of examples 2-23, wherein the laser beam has a beam parameter product of from about 10mm mrad to about 50mm mrad, less than about 40mm mrad, less than about 30mm mrad, less than about 20mm mrad, less than about 15mm mrad, and less than about 10mm mrad.

Example 25

The laser systems and assemblies of examples 2-23, wherein potential sources of silicon-based contamination that have been removed and minimized are siloxanes, polymerized siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, polysiloxanes, and combinations and variations of one or more thereof.

Example 26

The laser systems and components of examples 2-25, wherein the source of carbon-based contamination, which is mitigated by the presence of oxygen in the lumen, is solvent residue, oil, fingerprints, other sources of hydrocarbons, and combinations and variations of one or more thereof.

Example 27

An example of a solid-state high brightness blue laser is shown in table 1. The table shows the achievable power, brightness and performance of a 2.5W laser diode in a two-dimensional spectral beam combining configuration. The table illustrates how the power and brightness of a laser system based on a building block 350W module can be extended to multiple kilowatt power levels by launching into the process fiber using a fiber combiner.

TABLE 1

The system providing the beam of table 1 has a degradation rate of the two beam characteristics of table 1, i.e., from about 5% to about 1.5% per khrs or less, about 2.5% per khrs or less, 2.0% per khrs or less, 1.8% per khrs or less, 1.0% per khrs or less, and smaller values. The system providing the beam of table 1 (two beam characteristics) has a lifetime of from at least about 5000 hours to about 100000 hours, at least about 5000 hours, at least about 10000 hours, at least about 20000 hours, at least about 40000 hours, from about 10000 hours to about 50000 hours, and longer.

Example 28

The same modules in example 27 can also be combined in free space, which can save brightness but make module replacement somewhat more complicated. The achievable power and beam parameter products for free space combining are shown in table 2.

TABLE 2

The system providing the beam of table 2 has a degradation rate of the two beam characteristics of table 2, i.e., a value from about 5% to 1.5% per khr or less, 2.5% per khr or less, 2.0% per khr or less, 1.8% per khr or less, 1.0% per khr or less, and less. The system providing the beam of table 2 (two beam characteristics) has a lifetime of from at least about 5000 hours to about 100000 hours, at least about 5000 hours, at least about 10000 hours, at least about 20000 hours, at least about 40000 hours, from about 10000 hours to about 50000 hours, and longer.

Example 29

An example of a solid-state high brightness blue laser for a system using a high power blue laser diode is shown in table 3, with about 6.5W each. The base modules are now approximately 900W and these modules are combined by a fiber combiner to build a high power, high brightness blue laser diode system. As shown in table 3.

TABLE 3

The system providing the beams of table 3 has a degradation rate of two beam characteristics, namely, from about 5% to about 1.5% per khrs or less, 2.5% per khrs or less, 2.0% per khrs or less, 1.8% per khrs or less, 1.0% per khrs or less, and smaller values. The system providing the light beam of table 3 (both characteristics) has a lifetime of from at least about 5000 hours to about 100000 hours, at least about 5000 hours, at least about 10000 hours, at least about 20000 hours, at least about 40000 hours, from about 10000 hours to about 50000 hours, and longer.

Example 30

Referring to fig. 7, fig. 7 is a graph of laser power versus operating time. It can be seen that the blue laser diode assembly provides a slow degradation rate (plotted at 701) operating curve. The degradation rate has a flat portion 702 for about 200 hours to about 550 hours. After about 800 hours, the degradation rate was about 0.7% per khr. The degradation rate 703 displayed over 800 to 1600 hours will remain unchanged (i.e., the slope of the plot will not change substantially) during the remaining life of the system.

Example 31

Referring to fig. 8, fig. 8 is a graph of laser power versus operating time. It can be seen that the blue laser diode assembly provides a slower degradation rate (plotted line 801) operating curve. The degradation rate has a flat portion for about 150 hours to about 800 hours. After about 800 hours, the degradation rate was about 0.7% per khr. The degradation rate shown will remain unchanged (i.e., the slope of the plot will not change substantially) over the remaining life of the system for 800 to 1600 hours.

Example 32

FIG. 12 is a diagram of a TO-9Can or packaged laser diode. The amount of silicon-based contamination has been reduced when packaging laser diodes, which are filled with an oxygen-rich atmosphere. The TO-9Can 1200 has a stainless steel wall 1201 forming a housing 1205 with a heat sink 1204. The TO-9Can has a laser diode 1203 and a window 1206. The housing 1205 is filled with, for example, an oxygen-rich atmosphere.

Example 33

Fig. 13 and 14 show how a standard TO-9 laser diode package 1200 can be arranged into multiple laser packages 1250 and 1250a by mounting the TO-9 package into a properly machined heat sink capable of holding each individual TO-9 package. The laser diode mounted in the TO-9 package must be hermetically sealed with minimal silicone and carbon contamination (which can be minimized), and be mitigated and managed by an oxygen atmosphere. Once the laser diode assembly is properly cleaned, the package 1200 is sealed by an oxygen rich environment inside the package. Each package is individually sealed to ensure reliable operation.

Example 34

Fig. 15 shows a multi-tube laser diode package 1501 having 20 individual laser diodes, e.g. 1502, mounted on copper rods (e.g. 1503) to produce vertical cavity emission sources. Each diode is precisely mounted on a copper bar, and then each bar is precisely mounted on the backplane heat sink 1504. Metal mask 1505 is added to protect the diode from back reflection and minimize packaging andstray or scattered light in the window 1506. The package is cleaned to remove all sources of silicone contamination, and preferably also to remove and reduce sources of carbon contamination. When the package is sealed, the package is flooded with an oxygen rich environment to provide conversion of any free carbon to CO ₂ The means of (1), the CO ₂ Is harmless to the laser diode and cannot be dissociated by blue light. The lifetime of the assembly may be greater than 5000 hours or greater than 10000 hours.

Example 35

Fig. 16 shows a multi-tube laser diode package 1600 with 20 individual laser diodes, e.g. 1607, mounted on a backplane heat sink 1694. The package 1600 has a turning mirror (e.g., 1606) and a window 1602 through which window 1602 a laser beam travels in a laser beam path (e.g., 1605). The package is cleaned to remove all sources of silicone contamination and preferably also to remove and reduce sources of carbon contamination. When the package is sealed, the package is filled with an oxygen rich environment to provide for the conversion of any free carbon to CO ₂ The means of (1), the CO ₂ Is harmless to the laser diode and cannot be dissociated by blue light. The lifetime of the assembly may be greater than 5000 hours or greater than 10000 hours.

Example 36

Fig. 17 shows a similar method and assembly to fig. 16, but now the assembly 1700 has a separate encapsulation package (e.g., 1701) surrounding each laser diode (e.g., 1707) and turning mirror (e.g., 1706). The package has a window (e.g., 1702) through which the laser beam passes along a laser beam path (e.g., 1705). The separate hermetic package (e.g., 1701) and laser diode (e.g., 1707) are mounted on a heat sink (e.g., 1704). The smaller volume surrounding each laser diode package can be more easily cleaned and reduces the likelihood of silicone contamination, and preferably also eliminates and reduces sources of carbon contamination to avoid the cleaning requirements of more complex components. The laser diode and steering mirror must be cleaned prior to sealing to minimize silicone contamination and preferably also to eliminate and reduce sources of carbon contamination. Each package, e.g., 1701, is sealed with an oxygen rich environment to convert any residual carbon to CO that is not harmful to the laser diode ₂ . This process results in a laser diodeAnd the service life is long. The lifetime of the assembly may be greater than 5000 hours or greater than 10000 hours.

It is noted that there is no need to provide or address the theoretical basis for novel and inventive features or other advantageous characteristics, which are subject matter of or relating to embodiments of the present invention. However, various theories are provided in this specification to further advance the art of this important area, particularly of lasers, laser machining and laser applications. These theories as set forth in the present specification, unless expressly stated otherwise, are in no way intended to limit or otherwise narrow the scope of the claimed invention. These theories are not needed or practiced with the present invention. It should also be appreciated that the present invention may lead to new, heretofore unknown theories to explain the operation, function and features of the embodiments of the methods, articles, materials, devices and systems of the present invention; and such subsequently developed theory should not limit the scope of protection afforded by the present invention.

The various embodiments of lasers, diodes, arrays, modules, components, activities, and operations set forth in this specification can be used in the above-described fields and in various other fields. Further, these embodiments may be used with, for example, existing lasers, additive manufacturing systems, operations and activities, and other existing equipment; future laser, additive manufacturing system operations and activities; and such items as may be modified in part based on the teachings of this specification. Further, the various embodiments set forth in this specification may be used in different and various combinations with one another. Thus, for example, the configurations provided in the various embodiments of the present description may be used with each other. For example, the components of an embodiment having A, A' and B and the components of an embodiment having a ", C and D may be used in various combinations with each other, e.g., A, C, D and a, a", C and D, etc., in accordance with the teachings of the present specification. The scope of the present invention should not be limited to the particular embodiments, configurations, or arrangements described in the specific embodiments, examples, or embodiments in the specific figures.

The present invention may be embodied in other forms than those specifically disclosed without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

Claims (57)

1. A sealed container, packaged for providing a laser beam individual laser diode; the sealed container defines an interior cavity and an interior surface; wherein the inner surface is free of silicone contamination, whereby SiO is not formed during operation of the laser diode ₂ (ii) a And wherein said internal cavity contains means for preventing the formation of carbon contamination on said internal surface.

2. A sealed container enclosing a plurality of individual laser diodes for providing a laser beam; the sealed container defines an interior cavity and an interior surface; wherein the inner surface is substantially free of silicone contamination, whereby SiO is not formed during operation of the laser diode ₂ (ii) a And wherein said internal cavity contains means for preventing the formation of carbon contamination on said internal surface.

3. The sealed container of any of claims 1-2, wherein the laser beam is a blue laser beam.

4. The sealed container of any of claims 1-2, wherein the laser beam is a green laser beam.

5. The sealed container of any one of claims 1 to 4, wherein the power of the laser beam is from 1W to 10000W, about 500W, or about 1000W.

6. The sealed container of any one of claims 1-5, wherein the laser beam has a beam parameter product of from 50mm mrad to 10mm mrad, from 20mm mrad to 1mm mrad, or from 10mm mrad to 0.1mm mrad.

7. The sealed container of any one of claims 1 to 6, wherein the power density of the laser beam is 0.5MW/cm ² To 1000MW/cm ² At least about 1MW/cm ² At least about 5MW/cm ² Or at least about 10MW/cm ² 。

8. A sealed container according to any of claims 1 to 6, wherein the means for preventing the formation of carbon contamination on the inner surface is an oxygen-containing atmosphere.

9. The sealed container of claim 8, wherein the oxygen-containing atmosphere has an oxygen concentration of at least 1%, at least 10%, at least 20%, at least 50%, or from 5% to 80%.

10. The sealed vessel of claim 8 or 9, wherein the oxygen-containing atmosphere flows into and out of the sealed vessel.

11. The sealed container of any one of claims 1 to 6, wherein the means to prevent carbon contamination from forming on the inner surface is to render the inner surface free of carbon contamination.

12. The sealed container of any of claims 1-11, wherein the sealed container has an 80% laser life of at least 5000 hours.

13. The sealed container of any one of claims 1 to 11, wherein the sealed container has an 80% laser lifetime of at least 10000 hours.

14. A sealed container according to any of claims 1 to 11, wherein the sealed container has a laser lifetime of 80% comprising 5000 to 10000 hours.

15. The sealed container of any one of claims 1 to 14, wherein the rate of degradation is 2.5% per khrs or less.

16. The sealed container of any one of claims 1 to 14, wherein the rate of degradation is 2.0% per khrs or less.

17. The sealed container of any one of claims 1 to 14, wherein the rate of degradation is 1.5% per khrs or less.

18. A containment vessel as claimed in any of claims 1 to 17, comprising a heat sink, wherein the diode or diodes are mounted on the heat sink so as to form a two dimensional array of laser diodes.

19. The sealed container of any one of claims 1 to 17, comprising a back plate, wherein the diode or diodes are mounted on the back plate.

20. The sealed container of any of claims 1 to 19, comprising an optical element for manipulating the laser beam.

21. A sealed container according TO any of claims 1 TO 20, wherein the container is or comprises a TO-9Can.

22. A high power, high brightness solid state laser device package for integration into a laser system to provide a high quality blue laser beam over a long period of time without significant degradation of the laser beam characteristics, the package comprising:

a. a housing defining an internal cavity; wherein the internal cavity is isolated from an external environment of the housing;

b. the housing includes a window, wherein the window defines a portion of an internal cavity;

c. a solid state device for propagating a laser beam along a laser beam path from a propagation surface of the solid state device, wherein the laser beam has a wavelength in a range of 410nm to 500 nm; wherein the power density of the laser beam at the propagation surface is at least 0.5MW/cm ² ；

d. The window is in optical communication with the solid state device and is in the laser beam path;

e. wherein the solid state device is located within the housing and in the internal cavity, and wherein an inner surface of the window is not exposed to an external environment, such that the solid state device and the inner surface of the window are isolated from the external environment;

f. whereby the laser beam is transmitted along a laser beam path from the propagation surface through the window to the external environment;

g. the cavity is free of silicon-based contamination sources to avoid SiO generation in the cavity during operation of the solid state device ₂ (ii) a Whereby the inner cavity is SiO-free ₂ Accumulating; therefore, the degradation rate of the beam characteristics is 2.3% per khrs or less; and

h. wherein the lumen comprises a gas comprising at least 1% oxygen; thus, during operation of the solid state device, CO is produced in the internal cavity from carbon-based contamination ₂ So that the propagation surface of the solid state device and the inner surface of the window remain free of carbon build-up.

23. The package of claim 22, wherein the sealed container has an 80% laser lifetime of at least 5000 hours.

24. The package of claim 22, wherein the sealed container has an 80% laser life of at least 10000 hours.

25. The package of claim 22, wherein the sealed container has an 80% laser lifetime comprising 5000 hours to 10000 hours.

26. The package of claim 22, wherein the diode laser is a TO-9Can.

27. The package of any one of claims 22-26, wherein the power density is at least about 10MW/cm ² The power of the laser beam is at least about 2W, and the degradation rate is 2.0% per khrs or less.

28. The package of any one of claims 22-26, wherein the power density is at least about 5MW/cm ² The power of the laser beam is at least about 1.5W, and the degradation rate is 1.8% per khrs or less.

29. The package of any one of claims 22-26, wherein the power density is at least about 15MW/cm ² The power of the laser beam is at least about 5W, and the degradation rate is 2.3% per khrs or less.

30. The package of any one of claims 22 to 29, comprising at least 10% oxygen.

31. The package of any one of claims 22 to 29, comprising at least 40% oxygen.

32. The package of any one of claims 22 to 29, comprising at least 60% oxygen.

33. The package of any of the above claims, wherein the silicon-based contamination source is selected from the group consisting of siloxanes, polymeric siloxanes, linear siloxanes, cyclic siloxanes, cyclomethicones, and polysiloxanes.

34. A packaged or sealed container according to any of the preceding claims, wherein the carbon-based contamination source is selected from the group consisting of solvent residues, oils, fingerprints and hydrocarbons.

35. The package or sealed container of any of the above claims, wherein the silicon contamination within the package or sealed container is less than 0.01g, less than 0.001g, less than 0.0001g, less than 0.00001g, or less than 0.000001g.

36. The package or sealed container of any of the above claims, wherein the silicon contamination within the package or sealed container is less than 0.01ppm silicon, less than 0.001ppm silicon, less than 0.0001ppm silicon, or less than 0.00001ppm silicon.

37. The packaged or sealed container of any of the preceding claims, wherein the power density is at least about 10MW/cm ² The power of the laser beam is at least about 2W, and the degradation rate is 2.0% per khrs or less.

38. A package or sealed container according to any of the preceding claims, wherein the degradation rate of the beam characteristics is 2.0% per khrs or less.

39. A package or sealed container according to any of the preceding claims, wherein the degradation rate of the beam characteristics is 1.8% per khrs or less.

40. A package or sealed container according to any of the preceding claims, wherein the component is characterized by a lifetime of not less than 10000 hours.

41. A package or sealed container according to any of the preceding claims, wherein the component is characterized by a lifetime of not less than 30000 hours.

42. The package or sealed container of any of the above claims, wherein the component is characterized by a lifetime of not less than 50000 hours.

43. The package or sealed container of any of the above claims, wherein the assembly is characterized by a lifetime of not less than 70000 hours.

44. A method of operating a sealed container enclosing individual laser diodes to propagate a laser beam having a beam characteristic defining a product of a nominal power and a nominal beam parameter, wherein the sealed container includes a window and defines an interior cavity and an interior surface; the method comprises the following steps:

a. propagating a laser beam from a face of the laser diode through the cavity and out of the window away from the sealed container for a total run time comprising at least 5000 hours;

b. wherein no SiO is formed on the inner surface of the cavity during laser diode propagation ₂ ；

c. Wherein during laser diode propagation, CO ₂ Formed within the lumen; and

d. wherein the laser beam maintains at least 80% of its nominal power and at least 80% of its nominal beam parameter product during runtime such that laser beam characteristics are minimally degraded during runtime.

45. A method of operating a sealed container enclosing a plurality of individual laser diodes to propagate a combined laser beam having a beam characteristic defining a product of a nominal power and a nominal beam parameter, wherein the sealed container includes a window and defines an interior cavity and an interior surface; the method comprises the following steps:

a. propagating the individual laser beams from the facet of the laser diode; combining the individual laser beams to form a combined laser beam within the cavity and directing the combined laser beam away from the window away from the sealed container for a total run time including at least 5000 hours;

b. wherein no SiO is formed on the inner surface of the cavity during laser diode propagation;

c. wherein during laser diode propagation, CO ₂ Formed within the lumen; and

d. wherein the combined laser beam maintains at least 80% of its nominal power and at least 80% of its nominal beam parameter product during runtime, such that the beam characteristics are minimally degraded during runtime.

46. The method of claim 44 or 45, wherein the laser beam is a blue laser beam.

47. The method of claim 44 or 45, wherein the laser beam is a green laser beam.

48. The method of any one of claims 44 to 47, wherein the nominal power is from 1W to 10000W, about 500W, or about 1000W.

49. The method of any one of claims 44-48, wherein the nominal beam parameter product is from 50mm mrad to 10mm mrad, from 20mm mrad to 1mm mrad, or from 10mm mrad to 0.1mm mrad.

50. The method of any one of claims 44-49, wherein the power density of the laser beam at the face, window, or both is 0.5MW/cm ² To 1000MW/cm ² At least about 1MW/cm ² At least about 5MW/cm ² Or at least about 10MW/cm ² 。

51. The method of any one of claims 44-50, wherein the lumen comprises gaseous oxygen.

52. The method of any one of claims 44-51, wherein the lumen comprises an atmosphere comprising at least 1% oxygen.

53. The method of any one of claims 44-52, wherein the runtime comprises a total of at least 7500 hours.

54. The method of any one of claims 44-52, wherein the runtime comprises a total of at least 10000 hours.

55. The method of any one of claims 44-52, wherein 80% of non-mail power is maintained for an additional 2500 hours of runtime.

56. The method of any one of claims 44-52, wherein 80% of the non-mail power is maintained for an additional 5000 hours of runtime.

57. A method according to any of claims 44 to 56 wherein the vessel is operated on a plurality of intermittent duty cycles, each duty cycle defining an operating duty cycle period, wherein the sum of the operating duty cycle periods is equal to the run time.

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