JP2002530848A - Side pumping of diode arrays in laser systems - Google Patents

Abstract

(57) Abstract: At least one array of closely spaced diodes (2) that emits radiation pump energy, and each waveguide that can be used as a laser upon exposure to the radiation pump energy emitted from the diodes is provided in the array. A laser system comprising a plurality of waveguides (within 6) arranged in close proximity to the laser.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

 The present invention relates to diode-pumped laser systems.

[0002]

[Prior art]

Diode-pumped solid-state crystal lasers are becoming increasingly popular due to their compact nature and high power characteristics.

However, for optical signal processing, it is preferable to utilize a pumping waveguide to produce a laser output rather than a solid-state crystal laser, which is more difficult to combine with an optical layered circuit, for example.

[0004] Suitable waveguides include, for example, a doped core of optical fiber or a doped planar waveguide structure.

[0005] Such waveguides, ie, those capable of producing laser output by pumping using pump energy, provide efficient coupling of the pump energy optical signal with, for example, the doped core of an optical fiber via a fiber cladding. Is required.

[0006]

[Problems to be solved by the invention]

Various coupling techniques have been proposed to minimize coupling losses. However, there is a general feature that requires, for example, the additional components / structures needed to integrate with the optical stacking circuit, thereby making more complex,
This will result in a less compact design.

Further, typical individual sources of pump energy light signals require that each waveguide be pumped, and the light sources are individually coupled to each waveguide.

[0008]

[Means for Solving the Problems]

According to the present invention, at least one array of closely spaced diodes for emitting radiation pump energy; and being prepared to be exposed to the radiation pump energy emitted from the diodes to be used as a laser. (Ar
ranged) providing a laser system wherein each waveguide is a plurality of waveguides proximate the array.

[0009] A single diode array is utilized as a single source for pumping multiple waveguides at once, without the need for individual coupling means.

[0010] The waveguides may be prepared for use as lasers at different frequencies.
This can be used, for example, as a multiplex communication optical signal facility.

The system can further include a coupler that couples the individual laser outputs of the waveguide to form a combined laser output. The system may further include a waveguide for reflecting radiation pump energy emitted from the array into the waveguide, and reflecting means in close proximity to the array.

[0012] The plurality of waveguides may comprise a series of optical fibers or planar waveguides.

The waveguide may form a multi-mode interference device.

The waveguide may be formed as part of a multi-mode waveguide structure that can be connected to a single-mode waveguide.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

While there are other forms that fall within the scope of the invention, preferred forms of the invention are described with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing a first specific example of the present invention. In this embodiment, a series or bundle of waveguides in the form of a distributed feedback (DFB) fiber laser 2 including a tuned Bragg grating structure to provide a particular frequency characteristic is a diode bar 3. Pumped by In the embodiment, a 32DFB laser is provided. Of course, other arrangements are possible. For example, the fibers could be more closely spaced and formed in a single layer on the diode bar. Many different slacking arrangements are of course also possible. The diode bar 3 acts as a high-intensity pump so that the DFB laser can be used as a laser. The fiber is linked to one splitter 6 by 32, thereby providing an output 7 with multiple combined frequency channels.

The principle of FIG. 1 can be extended to other waveguide systems. For example, in FIG.
A diode bar 10 is placed on a waveguide 11 and includes a series of DFB lasers 12.
Are formed in the core. The diode bar 10 is used to pump the DFB laser 12 and emit an output 13.

As shown in FIG. 3, a waveguide 20 is provided on a substrate 21 and a diode bar 22 is provided.
Other arrangements provided for pumping the waveguide 20 are possible. The diode bar 22 is tilted with respect to the substrate 21 so that the pumped waveguide energy is reflected by the substrate 21 and then by the reflector 24, thereby enhancing the operating characteristics. Pumping allows waveguide 20 to be used as a laser, thereby providing output 25.

FIG. 4 illustrates another arrangement. A diode bar 30 is provided at one end of a substrate 31 having a series of DFB waveguides 32 disposed therein. Diode bar 30 is DFB
The laser is used as a laser 32 and is used to emit an output 33.

The arrangements of FIGS. 1 to 4 simultaneously provide an inexpensive arrangement of multiple waveguide diode pumping. This has important advantages when assembling active waveguide laser devices or other large area pumping. Its application is in the field of multimode interference devices. As described in FIG. 5, these devices can be formed on a waveguide 40 and a series of active waveguides 41 can be included between the two couplers 42,43. A diode bar 44 can be provided on the active portion, thereby providing large area pumping of the active waveguide portion 41, thereby providing different output coupling from input 46 to output 47 as needed.

FIG. 6 shows another specific example of the case of a high-power device requiring a large power coupling. The diode bar 50 is used to pump a large area multimode waveguide 51 that tapers to the single mode waveguide 51. This provides a pump wavelength of high output power 53 that can be used to pump other devices.

Having been so widely described, without departing from the spirit and scope of the invention,
Those skilled in the art will appreciate that there are numerous other embodiments from the invention illustrated by the examples. Therefore, the embodiments of the present invention are illustrative in all respects and do not limit the present invention.

In the claims and abstracts of the present invention, the term “consisting of”, except in special cases
Is used to mean containing. That is, the specified features can be combined with other features in various aspects of the invention.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a first specific example of the present invention.

FIG. 2 is an explanatory diagram showing a second specific example of the present invention.

FIG. 3 is an explanatory diagram showing a third specific example.

FIG. 4 is an explanatory diagram showing a fourth specific example.

FIG. 5 is an explanatory diagram of the use of the principle of the present invention in multimode interference.

FIG. 6 is an explanatory view of a further specific example of the present invention.

Claims (8)

[Claims] 1. An array of at least one closely spaced diode arranged to emit radiation pump energy; and being adapted to be used as a laser upon exposure to radiation pump energy emitted from the diode. A laser system, wherein each waveguide is a plurality of waveguides proximate the array. 2. The laser system according to claim 1, wherein the waveguides are prepared for use as lasers at different frequencies. 3. The system of claim 1, further comprising a coupler for coupling the individual laser outputs of the waveguide to form a combined laser output.
The laser system according to any one of claims 1 to 2. 4. The system according to claim 1, wherein the system further comprises a waveguide for reflecting radiation pump energy emitted from the array into the waveguide, and reflecting means in close proximity to the array. The laser system according to claim 1. 5. The method of claim 1, wherein the plurality of waveguides comprise a series of optical fibers.
The laser system according to any one of the preceding claims. 6. The laser system according to claim 1, wherein the plurality of waveguides are a series of planar waveguides. 7. The waveguide of claim 1, wherein the waveguide forms a multimode interference device.
7. The laser system according to any one of items 6 to 6. 8. The laser system according to claim 1, wherein the waveguide is formed as a part of a multi-mode waveguide structure that can be connected to a single-mode waveguide.