JPH05502980A - Diode laser assembly with cylindrical lens - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] diode with cylindrical lens laser assembly The U.S. government supports the U.S. Department of Energy for the operation of Lawrence Livermore National Laboratory. Published pursuant to Agreement W-7405-ENG-48 between the University of California and the University of California. has the right to the invention.

The present invention relates to microlenses. More specifically, the present invention provides a diode laser and cylindrical microlenses used with optical components integrated therein. do.

This application is filed by James J.A. Snyder (Jamesl, 5n7de+) Another application filed on the same date (titled “Cylindrical microlens with selected shape”) Method of Fabrication of Cyl ind[1cal MiC+olensesof 5elected 5hap e) “”).

Description of related technology A lens is an optical element that can focus or shift light. Ru. The most well-known type of lens is circular, for example circular focusing A lens focuses light onto a point. Such lenses are used for imaging Useful for many applications such as and photographic techniques. The well-known circular lens has an optical axis has a symmetrical shape around.

Another important type of lens is the cylindrical lens. A cylindrical focusing lens transforms light into a line. Focus along. This line is commonly referred to as a "line focus." Typical cylindrical lens The lenses are symmetrically formed with respect to a principal axis that is perpendicular to the optical axis. and For example, a cylindrical glass lens has the shape of a cylinder that is circular around its central axis. There is. Light is incident on the first curved surface of the cylinder and is incident on the first curved surface of the cylinder. Go out from the 2nd side.

However, for many applications, a circular cross section is undesirable. Therefore cylindrical lens The curve needs to have a specific shape that is completely different from the circular curve in the previous example. It is. This required shape may be flat or non-circular such as an ellipse or hyperbola. It would be the curve of In other words, a cylindrical lens is formed of various curved surfaces. You can stay there.

The exact shape chosen is highly dependent on each application.

Circular and flat shapes are easily manufactured and are common in cylindrical lenses. deer However, these shapes suffer from imperfections such as spherical aberration that causes misfocusing of the marginal rays. have an advantage. Through careful design and manufacturing of input and output surfaces, Spherical aberration can be substantially reduced. Other types of aberrations such as asymmetric aberrations also It can also be reduced by careful lens design and manufacturing. A certain level If the lens is designed to substantially reduce all major aberrations, it is Fraction-Limited (di’ll+aclion-1limited) Diffraction-limited lenses are called ensi17) to make efficient use of the light it receives.

An important quantity for any lens is its numerical aperture. lp+e).

The numerical apertures N, A, are quantitatively given by the following equations.

N, A, (numerical aperture) = n-sinθ Here, θ is the angle between the outermost ray of light incident on the lens and the optical axis. lar semi-aperture), and n is the area in which the light is focused. is the refractive index of the medium. Numerical aperture is determined by lens resolution and light-gathering ability (ligNga is a measure of the aperture size and focal length influenced by. The numerical aperture of the lens is greater than the numerical aperture of the source to which the lens is referenced. In some cases, all light from the source is parallel. On the other hand, the numerical aperture of the lens is smaller than the numerical aperture of the source, the light emitted from the source Some of them will not be parallel, but will be directed toward others and disappear. large lens If it has a numerical aperture, it is called "last".

Large size optics (larger than 5mm) with large numerical aperture (1 or more) The carefully engineered lens surface has been polished and polished to a sharp contrast. It can be processed by polishing technology. However, the small size For optical components (smaller than 5mm), conventional grinding and polishing techniques Therefore, it is impossible to manufacture a cylindrical lens with excellent optical quality.

For small microlenses (smaller than 1 mm), other technologies have been developed. It's been coming. Microlenses are made of photosensitive glass or glass with a gradient of refractive index (gr created using a computer using Processed as a diffractive optical component or kinoform (kinolo+ms) It's here. These technologies require lenses with numerical apertures approaching 0.5 or greater. could not be manufactured.

When processing microlenses from photosensitive glass, a mask is first placed on the glass. It will be done. The material outside the lens is then exposed to light. continue , when said glass is heated, the part exposed to light expands and increases its volume; The areas that become lenses that are not exposed to light are compressed. This compression allows the lens area swells up to form a simple lens.

Microlens with graded index of refraction (graded index+ole) nse+) is a material that changes the refractive index (inder-changing ma +++ It is formed by diffusing the mouth 1) into the glass. The diffusion process The refractive index changes smoothly from the center of the lens to the edges. this Smoothly changing refractive index focuses much more light than traditional lenses be done.

Binary (binaB1) diffractive optics (sophisticated optical components that can diffract light in a desired direction) using a diffractive optical component with a patterned lens surface) or a computer. In the created kinoform, the computer-generated pattern As a result, the surface of the glass plate is etched. Etched surface is a focal point It is designed to behave like a conventional lens by diffracting light towards the lens.

Cylindrical microlenses fabricated from photosensitive glass and flat surfaces with gradient refractive index Microlenses can be manufactured inexpensively and in large quantities. But this The speed (ability to focus light) of these optical elements is 0.2 in terms of numerical aperture when used as a single optical element. 5 to 0.32 and cannot be further corrected for spherical aberration. diffractive Optical component kinoform (Dillrac mouth ve optic kinolo+m s) can be corrected for aberrations, but an efficient kinof with a numerical aperture close to 0.5 Ohm lenses require lithography on the order of 1/4 micron, which is currently It's beyond the limits of technology.

Optical fibers with circular cross sections have been used as cylindrical lenses. Optical fiber is cheap It is easily available at a low price. However, circular optical fibers cannot be corrected for spherical aberration. I can't. In other words, such optical fibers are manufactured by Diffraction Limited. isn't it.

Custom designed cylindrical lens with limited diffraction, and it would be advantageous to provide a method of manufacturing such lenses inexpensively . The lens can be designed with a variety of input and output surfaces.

Such lenses may be designed to correct spherical aberration, for example.

Cylindrical microlenses are used for manufacturing integral optical components and for diode used for focusing the laser bar. In integral optical components, meticulous The designed cylindrical microlens efficiently and conveniently directs light into thin waveguides or is guided into or removed from the slit.

In other applications, cylindrical microlenses extract higher power lasers. form part of a low-cost, high-efficiency diode laser system. the current , a high-power laser has a gain extracted optically by a high-intensity flash lamp. It has a material (solid crystal or glass that amplifies light). This is inefficient , requiring high voltage. Compared to flash lamps, diode lasers are less effective. efficient and long-lasting. The power source is also used to generate the flash lamp. It can be of lower voltage than the power supply. Replace flash lamp with diode laser This can save power and increase the efficiency of high-power lasers. And that With such a replacement, reliability and longevity could also be increased. cormorant.

Additionally, diode lasers emit essentially a single wavelength. And the wavelength is The spectral absorption of the gain material is the extraction energy (pum) within the gain material. consistent or harmonious with efficient conversion from peneB to stored energy. You can choose as follows. The extracted energy is extracted through an array of diodes. Vine powered by laser. Such an array consists of a large number of closely overlapping diode laser bars. Consisting of In such a configuration, the light emitted from the diode laser bar is It is useful if substantially all of the light is collected in the solid gain material. this purpose For the diode laser beam from each diode laser bar is Advantageously, the present invention is directed to the material. Of the beam, a portion of the beam is directed toward the gain material. All the parts that are not highlighted are energy that is lost. However, the diode The laser bar has a numerical aperture of approximately 0.5, so a suitable cylindrical lens has a numerical aperture of approximately 0.5. ．． It should have a numerical aperture of 5 or more. But that is the limit of current technology exceeds.

If such a cylindrical lens is replaced, a diffraction lens with a numerical aperture of 0.5 or more can be used. An action-limited cylindrical lens parallelizes the beam from the diode laser. I can feel it. Parallel beams can either concentrate toward one point or diverge. Nor. That is, the rays within such a beam travel substantially parallel. compared to that , the focused beam converges at a focal point and then diverges to infinity. The diode laser bar - is an efficient laser radiation source, but in its application, diode laser There is a problem in that the beam emitted from the beam diverges greatly. from diode laser The divergence of the beam is due to its exit aperture. The exit opening has one axis (“first along the “first” axis) and along the other axis (perpendicular to the “first” axis) It is extremely wide along. Along the first axis (narrow aperture) of the emitted beam The cross section is highly divergent due to diffraction. In comparison, the beam from the wide aperture The cross-sections of are only slightly divergent. Traditional circular cross-section optical fibers It has been used to collimate the beam from an iode laser bar. deer However, the circular cross-section optical fiber is not diffraction-limited. The circular shape of has the disadvantage of spherical aberration, and such a fiber focuses A large part of the light disappears.

Summary of the invention The present invention provides a diffraction-limited, high numerical aperture (fast (l) ast)) A method of forming non-circular cylindrical microlenses is provided. this method has almost any shape on one or both of its optical surfaces; It can be applied to producing a cylindrical lens with a diameter of about 1.5. This cylindrical The lens should be diffraction-limited in its numerical aperture.

In some embodiments, the cylindrical lens has a hyperbolically curved optical surface. have. Also, in other embodiments it may be oval in shape.

In yet other embodiments, the cylindrical lens can be used for a given input light distribution. Other shapes designed to change the output light distribution to some desired output light distribution are also possible.

Said desired shape in the form of a glass preform larger than the final product is first formed. Dimensions of this magnitude can be obtained using conventional grinding techniques. Any desired shape can be formed. The glass preform is then heated to the lowest drawing temperature. microlenses of desired dimensions are pulled out from there. pulled out However, the cross-sectional shape of the glass remains constant. As a result, the cross-sectional shape remains constant. Its cross-sectional size gradually decreases until

The advantage of this is that imperfections (shape errors) during the preform manufacturing stage are By being pulled out, it is reduced to an insignificant amount (less than one wavelength). be.

For example, a 0001 inch defect in the preform will result in a 0001 inch defect in the finished cylindrical lens. will be reduced to such an extent that it will not be a problem. An additional benefit is that the pultrusion In the process, firepower boring or firepolis hing) makes the surface of the cylindrical lens optically smooth.

The invention relates to integrated optics, optical detectors and diode lasers, etc. Many applications are possible. Once the lens is connected to the diode laser bar In some cases, a solid-state laser with a high average output power is extracted or pumped. A high-intensity laser radiation source for ping) is provided. integrated optics In , a lens guides light into an aperture such as a waveguide and extracts it from there. used to do. Such lenses focus light onto a detector. can also be used.

Brief description of the drawing Figure 1 is a perspective view of a cylindrical lens. Figure 2 is a cross-sectional view of the cylindrical lens with the elliptical surface of Figure 1, and Figure 3 is a cross-sectional view of the cylindrical lens. A perspective view showing an example of a glass preform in the shape of FIG. 4 is a perspective view showing another embodiment of a glass preform in the shape of a cylindrical lens; Figure 5 is a perspective view of the glass rod used to create the glass preform. figure, FIG. 6 is a flowchart of a preferred method of forming a cylindrical lens of the present invention; Figure 7 is a cross-sectional view of a cylindrical lens with a hyperbolic surface, and Figure 8 is a cross-sectional view of a cylindrical lens with a hyperbolic surface. Cross section of connected cylindrical lens, Figure 9 shows a diode laser bar and cylindrical lens connected together to form an assembly. A perspective view of Figure 10 is a diagram depicting the lens design, and Figure 11 is a diode laser FIG. 3 is a cross-sectional view of a laser beam emitted from an exit aperture of the laser beam.

Detailed description of the invention The invention is best understood by reference to the drawings. In the figure, the same One part is given the same reference numeral.

A cylindrical lens 10 is shown in FIGS. 1 and 2. FIG. The cylindrical lens 10 is the main body II and has a first surface 12 and a second surface 14. The cylindrical lens 10 is circular It has a uniform cross section along the column axis 16. The cross section shown in FIG. 2 is similar to that shown in FIG. It has the same shape as the end face 17 facing outward. As shown in FIG. enters the body 11 of the cylindrical lens 10 from the first surface 12 and passes through the second surface 14. and exits from the lens 10. In other geometries, even if the direction of light propagation is reversed, good.

The light passing through the cylindrical lens 10 follows the shape of the first surface 12 and the second surface 14. greatly affected. Depending on the shape of surfaces 12 and 14 and the direction of propagation of the light, The outgoing light may be focused, unfocused, or distorted. Also, that Characteristics may change. As shown, first surface 12 is flat. The second surface I4 is convex. Thus, as shown in Figures 1 and 2 Lens 10 is a collimating lens. input The light formed on surface 12 emerges from output surface 14 as parallel rays. Other examples For different characteristics, surfaces 12 and 14 can be varied, such as concave or flat. They may have any shape and may have different radii of curvature.

According to the present invention, a method for processing and molding a cylindrical microlens is provided. This person (a) A glass preform 20 in the shape of a non-circular cylindrical lens (FIGS. 3-4) and (b) maintaining the cross-sectional shape of the glass preform 20. A large numerical aperture or other providing a cylindrical microlens with desirable properties.

3 and 4, an example glass preform 20 is shown with 20a and 20b. is shown schematically. Each glass preform 20 has a first surface 22 and It has a cylindrical cross section including the second surface 24. This cross-sectional shape is uniform along the cylinder axis 26. It is fixed. In the configuration shown in FIG. 3, the glass preform 20a is flat a first surface 22a and a curved second surface 24a. . In another form shown in FIG. 4, the glass preform 20b is It has a first surface 22b and a second surface 24b which are curved.

The particular shape of preform 20 will, of course, depend on the cylindrical shape that will be formed therefrom. depends strongly on the desired application of the lenses. The shape of the preform 20 is made by drawing substantially maintained throughout the process. Therefore, the cross-sectional shape of the preform 20 is , a certain input ray distribution inside the completed cylindrical microlens is selected to transform the desired output ray distribution. In some embodiments, the preform Either or both surfaces 22 and 24 of the form 20 have a hyperbolic shape. Good too. In other embodiments, either of surfaces 22 and 24 or Both may be oval in shape. In one embodiment shown in FIG. Even if the surfaces 22b and 24b are in a hyperbolic shape facing each other as shown in the figure, good.

Grinding, molding or extrusion to form glass preform 20 Any of a number of conventional techniques may be used, such as. The completed cylindrical micro The quality of the lens depends on the quality of the surface of the glass preform 20. glass play Preferably, a molding technique is selected that allows a smooth and precise surface to be molded onto the foam. stomach. However, the method of the present invention reduces the amount of A certain tolerance range (lεevay) is given for the shape error. For example, The 0001-inch defect in beam 20 is the result of a cylindrical microlens. It is reduced to such an extent that it does not become a problem.

In a preferred embodiment, a numerically controlled universal grinder (e.g. For example, Weldon Machine Tools in York, Pennsylvania. achine Tool! Computer numerically controlled for non-circular grinding manufactured by CNC cylindrical grinder, Model 16 with optional workhead 32) is used to mold the preform 20. glass preform 2 0 is ground from a circular glass rod, such as lot 30 shown in FIG. May be modified. Using the universal grinder, the rod 30 is optional. is ground into the shape of In this way, the glass preform 20 can have an infinite variety of shapes. can be formed into

In the process of molding the preform 20 using moldy knobs, the desired shape is A mold is created using conventional means. Conventionally, after that, molten glass or the above-mentioned mold was used. The preform 20 is then poured or pressed into the mold.

The molding process has the advantage of consistency and precision from preform to preform. do. The initial processing to manufacture the mold requires a lot of cost, but once the mold is manufactured, Once the preform 20 has been manufactured, additional preforms 20 can be easily made.

After the glass preform 20 is manufactured, it is used in the fiber optic industry. It is drawn using a method similar to that used for The glass preform 20 includes at least is also heated to the lowest drawing temperature. microlens fibers of desired dimensions are fabricated therefrom. glass play The cross-sectional shape of the foam 30 remains constant even when it is pulled out, but the cross-sectional dimension gradually decreases. It gets colder. In this process, the surface is made of fire polylens (li+!-poli +bing) makes it optically smooth. Fireboring has a surface temperature of This is thought to occur because the temperature is higher than the internal temperature. Fire polling is a skin effect (skin effect).

During the drawing process, the glass preform 20 is at least softened in an oven. heated to the temperature of Glass preform 20 has a softening temperature such as 5LF6 It is preferable that the material is made of a material with low . 5LF6 is commercially located in Pennsylvania, Pennsylvania. It can be obtained from Schotj Glai+ in Liée. Wear.

A preferred method for forming the cylindrical lens 10 (see FIG. 1) is according to the flowchart of FIG. as shown in the chart. In the first step, shown in box 32, the glass plate Foam 20 is molded into the desired shape. In the next step indicated in box 34 Then, glass preform 20 is placed in an oven and heated. At this time , the temperature is preferably carefully controlled to be the minimum temperature required for pultrusion. . Keeping the temperature at a minimum ensures that the preform 20 maintains its shape during drawing. This is because it is thought to help. In other words, preform 2 0 glass material is sufficient to permit pull-out or the surface tension is preformed. The drawing temperature is such that the viscosity is low enough to not substantially deform the shape of the beam 20. Preferably, the degree is selected. If the viscosity is too high or too long If the glass retains its viscosity for a period of time, the surface of the heated preform 20 The tension causes deformation of the preform 20 and the pulled cylindrical lens. too Of course, the temperature selected for any particular application may be included in the preform 20. Varies depending on the materials involved. The softening temperature of some materials is low, while the softening temperature of other materials is low. This is because the degree is high. In the next step, shown in box 36, the preform 20 is drawn using similar fiber optic technology. Preform 20? Once drawn, the dimensions of the cylindrical microlens fiber decrease. for example , said dimensions may be reduced from 1150 to 1/'100. Mai was pulled out Final cross-sectional dimensions of the cross-lens fiber (from the first optical surface to the second optical surface) The distance to the surface) is as small as 50 microns, and the distance to the surface is as small as 1000 microns (1 m A size of m) is also possible. After being pulled out, the microlens fiber may be rolled onto a cylinder or cut. shown in box 38 In the next step, the microlens fibers are fabricated as desired depending on each application. cut into pieces having a length of .

The cylindrical lens 10 shown in FIG. A section of a chromelens fiber is shown. The cylindrical lens 10 is approximately A cross-sectional dimension between 185 and 220 microns (said first surface 12 and second surface 12) (distance between surface 14).

In a preferred embodiment, as shown in FIG. 1, first surface 12 is flat. In addition, the second surface 14 is curved. More specifically, the second surface 14 is elliptical. It is in a state of

In that embodiment, the elliptical ring line 40 is on or near the flat surface 12. It is preferable to be located.

As a result, a diverging beam 42 emanating from the focal line 40 emerges from the elliptical surface 14 and flattens out. This becomes a row ray 44. This is illustrated in cross-section in FIG. this parallel light Line 44 is corrected for spherical aberration. This type of configuration is similar to diode lasers. It can be applied to make the beams coming from any small aperture parallel. . Conversely, a parallel ray 44 entering the cylindrical lens 10 from the ellipsoidal surface 14 has a focal line 40. will be focused along. The lens IO has a flat surface and an elliptical surface. It can be applied to guiding light to the aperture of integrated optical components such as detectors and waveguides. I can do it. The cylindrical lens 10 having such a flat-elliptical shape has a diameter of 185 microns. and 220 micron focal length.

The best results obtained so far have been with a focal length of 220 microns. It is a cylindrical lens.

1 and 10, the cylindrical lens 104 has a flat first surface 12 and an axial A “power” second wave that can change the above flat wave into a perfect cylindrical wave. The surface 14 may be designed to have a surface 14 of . A “powered” surface is a A surface that acts on a system and bends it or determines its course.

Listed below are considerations that should be taken into account when designing any particular lens. Ru. As shown in FIG. 10, the optical path between the apex of the dielectric interface 45 and the focal point 46 is equal to all other optical paths towards focal point 46.

Here, nl and n2 are the refractive indices of the media on the left and right sides of the interface 45, respectively. Ma f is the distance from the interface 45 to the focal point 46. This equation is: ...Restore the standard form to the conic section with the central axis at (8).Here, are the squares of the semimajor and semimajor axes, respectively. And the eccentricity e of the conic section is Here, the lower signs in equations (4) and (6) are for nl>n2. Ru.

There are two types of surfaces without spherical aberration. If a medium with a large refractive index is on the right side, (i.e., if nl<n2), the coefficient of the y2 term in equation (2) is It is positive and the curve becomes an ellipse. This is because the focal point is inside a medium with a large refractive index. has the characteristics of an immersion lens (9). If the medium with a large refractive index is on the left side, In this case, the coefficient of the term y2 in Equation (2) is negative, and the curve becomes a hyperbola. child In both of the two curves, the focus of the lens coincides with the focus of the conic section. Okay From equations (3) and (6), the focal length f is a is the distance along the X axis from the apex of the conic section to its center. Also, ea is It is the distance from the center to the focal point.

Since the focal length is proportional to the semi-major axis and the eccentricity (Equation (6)) depends only on the refractive index, , if the lens diameter is designed to a certain scale, the focal length will also be designed to a certain scale. .

The maximum numerical aperture for a flat-elliptical lens is theoretically becomes. Here, n2 is the refractive index within the lens, and n1 is the refractive index of the surrounding medium. . Further, a is the length of the semi-major axis of the ellipse, and b is the length of the semi-major axis of the ellipse. usually When an elliptical lens is in air, as in the case of , the maximum numerical aperture is M, N, A’, ell=, /M” completed becomes. For example, an elliptical lens is molded with 5FL6 and the wavelength is 800nm. If the refractive index is 1.78 for light, the maximum numerical aperture is 1.47. becomes. Of course, if the lens is made of a material with an even higher refractive index, An even larger numerical aperture would be obtained.

Cylindrical lenses 10 in the form of flat-ellipsoids have heretofore been fabricated. 0.75c The preform 20 with a width of m is made by a numerically controlled universal grinder. Molded from 5FL60/Sodo raw materials. The elliptical lens has a focal point of 220 microns. The refractive index was 178. Also, the semi-major axis a is 141.0 The semi-baked shaft was 117.0 microns, and the eccentricity e was 056. Re The thickness of the lens is determined by the thickness of the lens, using an optical cement that matches the refractive index. 220 micrometers so that it can be attached directly to the output facet of the laser. Ron's focal length was chosen to be approximately the same. In addition, completely diffrac tion-limited behavior was observed by interferographic analysis. 1 Diffraction-limited at 50 micron aperture (numerical aperture 06) Behavior is interferometric analysis (in!erle+omeHic an alyiit).

In other preferred embodiments, the first surface 12 is flat and the second surface 1 4 may have a hyperbolic shape.

FIG. 7 shows a cross section in this preferred embodiment and a section through the cross section. The effect on light is shown.

A light beam 47 propagating from a focal point 48 diverges towards a cylindrical lens lO. Second The light entering from the surface 14 becomes a parallel beam 49 and exits from the flat first surface 12. To go. The parallel beam 49 is corrected for spherical aberration. This form is A free-standing (tr ee-+tanding) It can be applied as a lens. Conversely, The parallel beam 49 entering the cylindrical lens 10 from the flat first surface 12 has a hyperbolic shape. is unaffected until it reaches the second surface 14 of the As it moves, it is focused toward point 48. Such a form is an integrated light It can be applied as a free-standing lens to guide light to the aperture of a detector or waveguide in a medical component. can be done. The maximum numerical aperture of such a flat-hyperbolic cylindrical lens teeth becomes. Here, a is the semi-long axis and b is the semi-burned axis.

Also, e is the eccentricity, n2 is the refractive index of the lens, and nl is the refractive index of the surrounding medium. be. Under normal conditions in air, the maximum numerical aperture is becomes. When a hyperbolic lens consisting of 5FL6 is in air, its maximum numerical aperture is The maximum value is 083. In comparison, an elliptical lens consisting of 5FL6 has a maximum of 1.4 It has a numerical aperture of 7, which is an extremely large numerical aperture.

If the first surface 12 has a shape suitable for adhesion, as shown in FIG. In this case, the cylindrical lens lOa is attached to an external surface such as the optical facet of a diode laser. may be glued to. A diode laser 50, the cross section of which is shown, is connected to a semiconductor. the semiconductor connection 52 includes a light emitting connection 52 disposed on the facet 56; A laser beam is emitted from the aperture 54. Connection 52 is the gain material for lasing. and define the laser cavity. The laser beam 58 is emitted from the light emitting aperture 54. The light is emitted in the direction of arrow 60. FIG. 11 shows the emission aperture 54 of the laser beam 58. An example of a cross section is shown. The narrow portion of beam 58 is aligned with the first axis (las+ axis) 62, and the wide part of the beam 58 is the long axis (long 21 ports) 64. At the exit aperture 54, the beam 58 is e.g. 1 micron wide. 65 and a length 66 of, for example, 7 microns. However, the shadow of diffraction The sound causes the beam 58 to fire faster along the fast axis 62 than along the long axis 66. It is well known that it spreads.

By any available means such as gluing, the facets 56 are attached to the cylindrical lens 1. 0 first surface 12a. Matched the refractive index of lens 10 (i n+Iex malch+d) Optical cement 67 is preferably used. stomach. Alternatively, facet 56 and first surface 12a are index-matched. Separated by a material such as oil, the diode 50 connects the lens lOa to another machine. They may be connected by physical means. a facet connected to the first surface 12a; 56, the laser beam from the diode laser 50 is efficiently directed to the lens IOa. It can be coupled within.

In most embodiments, the cylindrical axis +6 (see FIG. 1) or the diode laser 50 Advantageously, the lens IO is arranged parallel to the long axis 64 (see FIG. 11). It is. In such configurations, the powered second surface 14 of the lens 10 is , arranged to act on the fast axis 62 of the highly divergent laser beam 58. be placed.

In some embodiments, second surface 14 is elliptical in shape and light emitting aperture 54 is elliptical in shape. It is placed almost close to the focal point of the ellipse. In such embodiments, the lens The laser beam 58 exiting the lens lOa is substantially aligned along the fast axis 62. collimal or substantially aligned along the fast axis ed).

In other embodiments, the cylindrical lens 10 may provide a far divergent beam 58. The shape is such that the divergence of the strike shaft 62 is reduced. For example, the second surface 14 The curve is similar to the divergence of beam 58 along its long axis 64 as well as its first axis. may be chosen to diverge along 62. By doing so, the shaft 62 and 64 can result in a beam 58 that is approximately equally divergent along both.

Cylindrical lens 10 is suitable for connecting output facet 56 and first surface I2. Any type of diode laser 50 can be connected as long as it has a suitable shape. It's okay. A diode laser bar 70 is shown in FIG. The diode The laser bar 70 emits a laser beam having a width substantially equal to its length 71. cylindrical lens 10 is connected to a diode laser bar 70 to form an assembly 72 . lens 1 0 cylinder axis 16 (see FIG. 1) is parallel to the length Id16B of the diode laser bar 70 It is located in The curved second surface 14 of the lens 14 can be of any shape. However, if the laser beam 74 emitted from the lens 10 is Preferably, the shape of the surfaces 14 is selected so that the surfaces 14 are substantially parallel.

For example, if the curved second surface 14 is It has an elliptical shape, and is shaped so that the focal point of the ellipse is close to the light emitting aperture 54 (see FIG. 8). If this is done, the laser beam 74 emitted from the lens 10 will have its first axis 6 2 will be substantially parallel.

In an embodiment of a cylindrical lens 10, the second surface of which is elliptical, as shown in FIG. It is preferred that the focus of the ellipse be located close to the first surface 12. It has been said that. Although the preform 20 may be designed in such a form, , due to manufacturing imperfections, the actual point of the pulled out cylindrical lens 10 is the first one. It will vary in relation to the surface 12. Therefore, in some applications, optical surfaces 12 can be designed to be at a position such as point 76 in FIG. That would be preferable. In this way, when actually molding the cylindrical lens 10, the light emitting The position of lens IO with respect to aperture 54 is such that output beam 74 has its first axis 62 may be adjusted to a position such that they are substantially parallel to each other. smell this position In other words, beam 74 is directed toward lens 10 at an angle that depends on the focal curve of lens 10. I'm leaving.

Diode laser bar 70 is an efficient and compact laser radiation source that If connected to the lens 10 in the laser and lens assembly 72, many can be applied. For example, an array of diode lasers and lenses If the three-dimensional objects 72 are connected to each other, they can output parallel light beams with high efficiency and intensity. Can be done. Such an assembly 72 extracts the laser beam from the solid laser material. We offer a package that is very suitable for

The invention may be carried out in other specific forms without departing from its spirit or essential characteristics. may be applied. The embodiments described herein are in all respects merely illustrative. However, the present invention should not be considered as being limited thereto. The scope of is determined by the appended claims rather than by the foregoing description. request All changes that come within the scope of the claims and their equivalents are included within the scope of the invention. should be

20 et al. , -10 FIG. 7 Ma summary The present invention provides a diffraction-limited, high numerical aperture (fast (l) ast)) A cylindrical microlens (10) is provided. This micro lens (1 The method for producing It can be applied to produce lenses. This cylindrical lens is A hyperbolic or elliptical shape designed to change the distribution to the desired output light distribution. You can. In the method, the glass preform (20) is The desired shape is first molded. After this, the glass preform is brought to the lowest drawing temperature. It is heated and the fiber (10) is drawn therefrom. of the obtained fiber The cross-sectional shape remains that of the preform from which it was drawn. Pulling out In the process, the surface is optically smoothed by fire polishing.

The invention relates to integrated optics, optical detectors and diode lasers, etc. Many applications are possible.

The lens (10) has a high flat surface when connected to the diode laser bar (70). High intensity laser for pumping solid state lasers with equal power The radiation source can be provided. The lens has an integrated optical part that directs light It can be used to guide and remove devices such as nib guides.

Additionally, the lens can collect and focus light onto a detector.

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Claims (17)

[Claims] 1. a diode with a light emitting aperture defining a first axis and a second axis perpendicular to the first axis; laser and A cylindrical microlens glued to the exit facet of the diode laser It consists of a laser beam in which the cylindrical microlens has a cylindrical axis parallel to the second axis; Laser assembly for providing a beam of light. 2. The diode laser has a width along its first axis that is substantially longer than a width along its first axis. 2. A laser according to claim 1, comprising a diode laser bar having a light emitting aperture along two axes. -Assembly. 3. A cylindrical microlens allows light rays along the first axis to diverge almost along the second axis. The laser radiation emitted from the diode laser is 2. The laser assembly of claim 1, wherein the laser assembly is configured to partially collimate one axis. 4. A cylindrical microlens captures the laser radiation emitted from a diode laser. 2. The laser assembly of claim 1, wherein the laser assembly is configured to collimate a first axis of the laser. 5. The laser according to claim 1, wherein the cylindrical microlens has an elliptical optical surface. Zar coarse solid. 6. The cylindrical microlens is located close to the light emitting aperture of the diode laser. 6. The laser assembly according to claim 5, comprising: 7. The cylindrical microlens is glued to the facet of the diode laser. 2. The laser assembly of claim 1, comprising a flat surface. 8. Placed in a thin layer between the cylindrical lens and the exit facet of the diode laser Claim 7 comprising an optical member having a refractive index that matches the cylindrical lens. Laser assembly as described. 9. Cylindrical lens for bonding the cylindrical lens to the exit facet of the diode laser 9. The optical cement according to claim 8, comprising an optical cement having a refractive index matched to the shaped lens. laser assembly. 10. A narrow region defining the fast axis and a substantially longer region defining the long axis a diode laser bar with a light emitting aperture having a a cylindrical microlens glued to the exit facet of the diode laser; It consists of The cylindrical microlens allows the laser beam emitted from the aperture to substantially parallel to at least one axis, having a shape that substantially collimates the axis; a laser assembly for supplying laser radiation; 11. 11. The cylindrical microlens according to claim 10, wherein the cylindrical microlens has an elliptical optical surface. laser assembly. 12. The cylindrical microlens is close to the exit facet of the diode laser. 12. The laser assembly of claim 11, wherein the laser assembly has a focal line. 13. The cylindrical microlens is glued to the exit facet of the diode laser. 11. The laser assembly of claim 10, having a flat surface. 14. disposed between the cylindrical lens and the exit facet of the diode laser. 14. An optical member having a refractive index that matches the cylindrical lens. Laser assembly included. 15. Circular for gluing the cylindrical lens to the exit facet of the diode laser 15. An optical cement having a refractive index matched to the columnar lens. Laser assembly included. 16. The facets of the diode laser are glued together to give them a harmonious shape. It has a first optical surface and a second optical surface located on the opposite side of the first optical surface. the law of nature, The second optical surface is an ellipse located within a range of 50 to 1000 microns from the first optical surface. It has a circular shape, and the ellipse is located on the outside of the lens and close to the first optical surface. A cylindrical micrometer for collimating the output of a diode laser with a focal point at Kuro Lens. 17. Claim 16: The first optical surface is a plane parallel to the cylindrical axis of the microlens. The cylindrical microlens described.