JP2005249961A - Solid coloring matter laser chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid coloring matter laser chip in which output is made high, wavelength stability is good and the service life is long. <P>SOLUTION: In the solid coloring matter laser coloring chip, optical waveguides 2, in which coloring matter is doped, are formed on a substrate 1 in a stripe shape and diffraction gratings 11 having different lengths and interference exposure times are formed on a portion of the surfaces of the optical waveguides 2. The diffraction gratings are formed on both ends of the optical waveguides. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a solid dye laser chip capable of oscillating a laser having a wavelength according to the pitch of the diffraction grating by forming a diffraction grating on an optical waveguide formed in a stripe shape doped with a dye and irradiating the optical waveguide with excitation light. About.

  A solid dye laser chip in which a plurality of optical waveguides doped with dyes are formed in a stripe shape is known, for example, in Patent Document 1 related to the present applicants.

  4A is a schematic diagram of a conventional solid dye laser chip in which the conventional optical waveguide disclosed in Patent Document 1 is formed in a stripe shape, and FIG. 4B is a diagram of a variable wavelength laser using the solid dye laser chip. FIG. In FIG. 4A, diffraction gratings having different pitches are formed on the surfaces of the dye-doped optical waveguide 2 formed on the acrylic substrate 1, and the wavelength corresponding to the pitch is obtained by laser excitation of a YAG laser or the like. Is emitted from the end face of the optical waveguide 2.

  In FIG. 4B, the excitation light from the YAG laser is magnified by the concave lens 3, then converted into a parallel beam by the cylindrical lens 4, and becomes a parallel beam focused by the cylindrical lens 5. A part of the light is directly incident on the solid dye laser chip 7 attached to the chip holder 6, and the remaining excitation light is reflected from the mirror 8, causing interference in the solid dye laser chip 7, thereby causing the laser to pass through the optical waveguide 2. Output from the end.

In addition, as a method for producing a solid dye laser chip, the present applicants mixed a dye with methyl methacrylate or a copolymer of methyl methacrylate and hydroxyethyl methacrylate, and dropped the mixture onto a substrate, followed by spin coating. We propose a method of forming an optical waveguide consisting of multiple stripes by wet etching after thinning on a substrate, drying this thin film, solidifying by annealing, and then exposing it with an excimer lamp using a photomask (See Patent Document 2).
JP 2003-273434 A JP 2003-273433 A

  In the conventional solid dye laser chip, after the optical waveguide is formed, DFB (Distributed Feedback) is produced on the entire surface of the optical waveguide. However, in this method, the dye of the optical waveguide is deteriorated by the ultraviolet laser at the time of producing the DFB, and there is a limit to high output, long life, and wavelength stability.

  In the solid dye laser, the laser medium is carried by the dye molecule. Therefore, the number of dye molecules before the DFB preparation is required in the medium in order to ensure the output and the lifetime. The conventional solid dye laser chips have produced a DFB over the entire optical waveguide and oscillated it by irradiating the entire optical waveguide with excitation light. Therefore, wavelength shift due to degradation of the DFB has been a problem.

  Further, in the conventional solid dye laser chip, the laser is output from both sides of the optical waveguide, but since only the output on one side has been available so far, the output of half is simply lost. Therefore, in order to maintain the life and ensure the output, as shown in FIG. 4B, it is necessary to attach a mirror for reflecting half of the excitation light to the laser chip on one side. There was a problem of becoming complicated.

  The magnitude of the laser output depends on the intensity of the excitation light. However, the dye has a lifetime, and the lifetime is determined by the irradiation energy per unit area of the excitation light and the repetition, so the larger the excitation input to irradiate one optical waveguide, the shorter the lifetime and the higher the output. For this reason, in order to maintain the lifetime and secure a high output, there is a drawback in that the number of optical waveguides excited at a time must be increased to extract the laser.

  Therefore, the present invention provides a solid dye laser chip having high output, good wavelength stability and long life.

  The present invention relates to a solid dye laser dye chip in which a dye-doped optical waveguide is formed in a stripe shape on a substrate, and a diffraction grating having a different length and interference exposure time is formed on a part of the surface of the optical waveguide. Features.

  In the above configuration, a diffraction grating can be formed at both ends of the optical waveguide, a mirror can be formed by vapor deposition of aluminum or the like on one side of the optical waveguide, or a plurality of optical waveguides that can be excited simultaneously can be arranged.

  In the present invention, by applying a mask to the optical waveguide and performing interference exposure with an ultraviolet laser, it is possible to suppress dye deterioration due to the ultraviolet laser during DFB production, so that high output can be obtained and the life can be extended. it can.

  In the present invention, a diffraction grating can be produced at an arbitrary place by applying a mask to an optical waveguide and performing interference exposure with an ultraviolet laser.

  FIG. 1 is a diagram showing an example of the manufacturing process of the solid dye laser chip of the present invention.

  The dye is mixed with methyl methacrylate or copolymerization of methyl methacrylate and hydroxyethyl methacrylate, and this mixture is dropped onto an acrylic substrate 1 and spin coated to form a thin film 9 on the substrate (FIG. 1 ( a))), this thin film 9 is dried and annealed at 70 ° C. for 20-24 hours to complete polymerization. Next, a photomask 10 is applied and exposed with an ultraviolet laser or a lamp (see FIG. 1B), and then an optical waveguide 2 composed of a plurality of stripes is formed by wet etching (see FIG. 1C).

  Next, a diffraction grating having a DFB structure is formed at both ends of the laser waveguide. In the production of the diffraction grating, a mask 10 is applied as shown in FIG. 1D in order to protect the dye from the exposure laser in the region excluding both ends where the diffraction grating is produced. After applying the mask 10, the diffraction grating 11 is produced at both ends of the optical waveguide 2 by making laser beams from two directions interfere.

  In this embodiment, a mask is provided on the optical waveguide and interference exposure using an ultraviolet laser is performed, so that not only a diffraction grating can be produced at an arbitrary place, but also the dye can be protected from the ultraviolet laser. Therefore, it is possible to suppress the deterioration of the dye caused by the ultraviolet laser, so that it is possible to obtain wavelength stability at a high output and to extend the lifetime.

  FIG. 2 is a schematic view showing another embodiment of the solid dye laser chip of the present invention. In this embodiment, the end surface of the optical waveguide 2 formed on the substrate 1 is mirror-polished, and this surface is coated with a highly reflective material such as aluminum by vacuum deposition or the like to form the mirror 12.

  The conventional solid dye laser chip outputs only from one side, and the output from one side is wasted, but in this embodiment, all spontaneous emission light and lasers can be obtained by forming a mirror by evaporating aluminum or the like. It can be used without waste, and the output characteristics are greatly improved.

  In the solid dye laser chip of the present invention, the output of the dye chip can be improved to several tens of% in terms of the performance of the dye chip, and an output several times larger than the conventional output can be taken out. This can be applied to both the DFB structure in which a diffraction grating is formed on the entire surface of a normal waveguide and the DBR system in which a diffraction grating is formed only at both ends of the waveguide.

  FIG. 3 is a schematic view showing another embodiment of the solid dye laser chip of the present invention. In this embodiment, a plurality of optical waveguides that are excited simultaneously are arranged.

  When a single waveguide is excited with a high-power laser or the like, the energy density of the excitation light is high, so the life of the dye chip is short and the output cannot be extracted efficiently. In this embodiment, however, the width of the optical waveguide is reduced. Since the output increases due to the light confinement effect, a long-life and efficient laser output can be obtained by simultaneously exciting a plurality of narrow (several tens to several hundred μm) optical waveguides. be able to. This can be applied to both the DFB structure in which a diffraction grating is formed on the entire surface of a normal waveguide and the DBR system in which a diffraction grating is formed only at both ends of the waveguide.

It is a figure which shows the manufacturing process of the solid dye laser chip of this invention. It is the schematic which shows another Example of the solid dye laser chip of this invention. It is the schematic which shows another Example of the solid dye laser chip of this invention. FIG. 2B is a schematic view of a conventional solid dye laser chip in which a conventional optical waveguide is formed in a stripe, and FIG. 5B is a schematic view of a variable wavelength laser using the solid dye laser chip.

Explanation of symbols

1: Substrate 2: Optical waveguide 3: Concave lens 4, 5: Cylindrical lens 6: Chip holder 7: Solid dye laser chip 8: Mirror 9: Thin film 10: Mask 11: Diffraction grating 12: Mirror

Claims (4)

  A solid dye laser dye chip in which an optical waveguide doped with a dye is formed in a stripe shape on a substrate, wherein a diffraction grating is formed on a part of the surface of the optical waveguide.   2. The solid dye laser dye chip according to claim 1, wherein the diffraction grating is formed at both ends of the optical waveguide.   A solid dye laser dye chip in which an optical waveguide doped with a dye is formed in a stripe shape on a substrate, wherein a mirror is formed on one side of the optical waveguide by vapor deposition of aluminum or the like. A solid dye laser dye chip comprising a plurality of optical waveguides that are simultaneously excited in a solid dye laser dye chip in which an optical waveguide doped with a dye is formed in a stripe shape on a substrate.

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