JP2016058560A - Optical fiber output type multi-wavelength laser light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber output type multi-wavelength laser light source device capable of maintaining wavelength stability of a laser light source by suppressing coupling efficiency fluctuation in a multiplexing part.SOLUTION: The optical fiber output type multi-wavelength laser light source device includes: a plurality of first temperature control elements 3 which are provided correspondently to a plurality of laser light sources 2 and control temperatures of the laser light sources; a multiplexing part 5 by which laser lights from the plurality of laser light sources emitted through a light transmission part 4 for transmitting laser lights emitted from the plurality of laser light sources are multiplexed and emitted to an optical fiber 10 and laser lights from the plurality of laser light sources are partially demultiplexed; a second temperature control element 6 which controls a temperature of the multiplexing part; a plurality of photodetectors 7 which are provided correspondently to the plurality of laser light sources and detect a part of laser lights of the plurality of laser light sources emitted from the multiplexing part; and a control circuit 8 by which laser output is controlled at a predetermined value on the basis of detection output from the plurality of photodetectors and the second temperature control element is controlled in such a manner that the temperature of the multiplexing part becomes a predetermined temperature. The multiplexing part is thermally insulated from the plurality of laser light sources.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical fiber output type multi-wavelength laser light source device that emits a plurality of laser beams having different wavelengths from a single optical fiber.

  In an optical fiber output type multi-wavelength laser light source device that multiplexes a plurality of laser beams coaxially and emits them from a single optical fiber, in order to stabilize the optical output, when performing auto power control (APC), Laser light before optical fiber coupling is used as feedback light. For this reason, if the alignment of the multiplexing optical system is shifted due to a change in the environmental temperature or the like, the coupling efficiency to the optical fiber is lowered, and the light output after emission from the optical fiber is fluctuated.

  FIG. 3 is a configuration diagram of a conventional multi-color laser apparatus. The multi-color laser apparatus shown in FIG. 3 has a large thermal conductivity between a plurality of laser light sources that emit laser beams having different wavelengths (488 nm and 635 nm) and a multiplexing optical element that combines the laser beams. By mounting on the casing 350 and controlling the temperature of the entire casing with the temperature controller 352, the fluctuation of the light beam pointing due to the fluctuation of the environmental temperature is suppressed.

  Further, as this type of conventional technique, for example, a technique described in Patent Document 2 is known.

US Patent No. 7903706B2 JP-A-63-224384

  However, the technique described in Patent Document 1 has the following problems. That is, since the casing 350 to be temperature controlled includes a plurality of laser light sources and multiplexing optical elements, the temperature controller 352 having a large temperature adjustment capability is required, and thus power consumption increases.

  Further, since the temperature of the entire casing is controlled by the temperature controller 352, the temperature of the laser light source and the temperature of the multiplexing optical element cannot be controlled independently. For this reason, when the environmental temperature changes, the temperature controller changes the temperature of the multiplexing optical element and also the temperature of the laser light source at the same time in order to suppress beam pointing fluctuations (coupling efficiency fluctuations of the multiplexing unit). It will change. This may impair the wavelength stability of the laser light source.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber output type multi-wavelength laser light source device capable of suppressing the coupling efficiency fluctuation of the multiplexing unit, reducing the power consumption of the temperature controller, and maintaining the wavelength stability of the laser light source. .

  In order to solve the above problems, an optical fiber output type multi-wavelength laser light source device according to the present invention is provided corresponding to a plurality of laser light sources that emit laser beams having different wavelengths, and the plurality of laser light sources, A plurality of first temperature control elements for controlling the temperature of the laser light source; a light transmission unit for transmitting laser light emitted from the plurality of laser light sources; and a plurality of laser light sources emitted from the light transmission unit. A multiplexing unit that multiplexes and emits laser light to an optical fiber and branches a part of the laser light from the plurality of laser light sources; a second temperature control element that controls a temperature of the multiplexing unit; A plurality of photodetectors provided corresponding to a plurality of laser light sources and detecting a part of the laser beams of the plurality of laser light sources emitted from the multiplexing unit, and detection outputs of the plurality of photodetectors Based on the laser output And a control circuit that controls the second temperature control element so that the temperature of the multiplexing unit is a predetermined temperature, and the multiplexing unit is thermally insulated from the plurality of laser light sources. It is characterized by being.

  According to the present invention, the plurality of laser light sources and the multiplexing unit are thermally insulated, and the multiplexing unit is controlled so as to reach a predetermined temperature, thereby suppressing the coupling efficiency fluctuation of the multiplexing unit due to a change in environmental temperature. In addition, the light output after emission from the optical fiber can be stabilized. In addition, since the temperature control target is reduced, the power consumption of the temperature controller can be reduced. In addition, since the control temperature of the multiplexing unit is independent of the laser light source, the wavelength stability of the laser light source can be maintained.

It is a top surface lineblock diagram of an optical fiber output type multi-wavelength laser light source device of an embodiment of the present invention. It is a side block diagram of the optical fiber output type multi-wavelength laser light source device of the embodiment of the present invention. It is a block diagram of the conventional multicolor laser apparatus.

  Embodiments of an optical fiber output type multi-wavelength laser light source device of the present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a top view of an optical fiber output type multi-wavelength laser light source apparatus according to an embodiment of the present invention. FIG. 2 is a side configuration diagram of the optical fiber output type multi-wavelength laser light source apparatus according to the embodiment of the present invention.

  An optical fiber output type multi-wavelength laser light source device includes a plurality of laser light sources 2-1 to 2-n, a plurality of first temperature control elements 3-1 to 3-n, and an optical transmission optical system 4 in a laser housing 1. , A multiplexing optical system 5, a second temperature control element 6, a plurality of photodiodes 7-1 to 7-n, a laser control circuit 8, and a connector 9.

  One end of an optical fiber 10 is connected to the connector 9. A connector 11 is connected to the other end of the optical fiber 10.

  The plurality of laser light sources 2-1 to 2-n emit laser beams having different wavelengths (λ1, λ2,..., Λn) and are spaced apart from each other by a predetermined distance. For this reason, each of the plurality of laser light sources 2-1 to 2-n is thermally insulated from each other.

  The plurality of first temperature control elements 3-1 to 3-n are provided corresponding to the plurality of laser light sources 2-1 to 2-n and, as shown in FIG. It is provided between the laser light sources and controls the temperature of the plurality of laser light sources 2-1 to 2-n, and is composed of, for example, a Peltier element.

  The optical transmission optical system 4 corresponds to the optical transmission unit of the present invention and transmits laser light emitted from the plurality of laser light sources 2-1 to 2-n, and is made of, for example, an optical fiber. The light transmission optical system 4 can use a condensing lens instead of the optical fiber.

  The multiplexing optical system 5 corresponds to the multiplexing unit of the present invention, and coaxially combines the laser beams from the plurality of laser light sources 2-1 to 2-n emitted from the optical transmission optical system 4 to connect the connector 9. Are emitted to the optical fiber 10 and part of the laser light from the plurality of laser light sources 2-1 to 2-n is branched and output to the plurality of photodiodes 7-1 to 7-n. It consists of a dichroic filter.

  As shown in FIG. 2, the second temperature control element 6 is provided between the housing 1 and the multiplexing optical system 5, and controls the temperature of the multiplexing optical system 5. For example, the second temperature control element 6 is composed of a Peltier element. .

  The plurality of photodiodes 7-1 to 7-n correspond to the plurality of photodetectors of the present invention, and are one of the laser beams of the plurality of laser light sources 2-1 to 2-n emitted from the multiplexing optical system 5. Are detected and output to the laser control circuit 8.

  The laser control circuit 8 corresponds to the control circuit of the present invention, controls the laser output to a predetermined value based on the detection outputs from the plurality of photodiodes 7-1 to 7-n, and the plurality of laser light sources 2-1 to 2-1. The plurality of first temperature control elements 3-1 to 3-n and the second temperature control element 6 are controlled so that the temperature of 2-n and the temperature of the multiplexing optical system 5 become a predetermined temperature.

  The multiplexing optical system 5 is thermally insulated from the plurality of laser light sources 2-1 to 2-n through the optical transmission optical system 4.

  The laser control circuit 8 includes a second temperature control element such that fluctuations in the light outputs of the plurality of laser light sources 2-1 to 2-n are less than or equal to a predetermined value based on the outputs of the plurality of photodiodes 7-1 to 7-n. 6 temperature is controlled.

  Next, the operation of the optical fiber output type multi-wavelength laser light source apparatus of the embodiment of the present invention configured as described above will be described.

  First, a plurality of laser light sources 2-1 to 2-n having different wavelengths are temperature-controlled by a plurality of first temperature control elements 3-1 to 3-n. Light emitted from each of the laser light sources 2-1 to 2-n is guided to the multiplexing optical system 5 through the optical transmission optical system 4 and rearranged into a coaxial beam.

  At the same time, part of the laser light of each wavelength is guided to the photodiodes 7-1 to 7-n and fed back to the laser control circuit 8. The laser control circuit 8 performs APC control for each wavelength of the laser light sources 2-1 to 2 -n.

  One end of an output optical fiber 10 aligned with a coaxial beam is fixed to a connector 9 attached to the multiplexing optical system 5, and light of each wavelength is emitted from the other end of the optical fiber 10. Is done.

  Here, since the casing 1 in which the multiplexing optical system 5 is mounted is temperature-controlled by the second temperature control element 6, the coupling efficiency fluctuation of the multiplexing optical system 5 due to a change in environmental temperature is suppressed, and the APC is used. A stabilized light output can be output from the optical fiber 10. Further, the optical transmission optical system 4 has low thermal conductivity and thermally insulates the laser light sources 2-1 to 2-n and the multiplexing optical system 5 from each other, thereby eliminating mutual thermal interference. be able to.

  That is, since the laser light sources 2-1 to 2-n and the combining optical system 5 are thermally insulated and the combining optical system 5 is controlled so as to reach a predetermined temperature, the combining optical system due to a change in environmental temperature. 5 can be suppressed, and the light output after exiting the optical fiber can be stabilized.

  In addition, since the temperature control target is reduced, the power consumption of the temperature controller can be reduced. Moreover, since the control temperature of the multiplexing optical system 5 is independent of the laser light sources 2-1 to 2-n, the wavelength stability of the laser light sources 2-1 to 2-n can be maintained.

  The optical fiber output type multi-wavelength laser light source device according to the present invention is applied to all devices that use laser beams of different wavelengths simultaneously or in time series, and can be used for laser microscopes, laser projectors, flow cytometers, and the like.

DESCRIPTION OF SYMBOLS 1 Laser housing | casing 2-1 to 2-n Laser light source 3-1 to 3-n 1st temperature control element
4 optical transmission optical system 5 multiplexing optical system 6 second temperature control elements 7-1 to 7-n photodiode 8 laser control circuits 9, 11 connector 10 optical fiber

Claims (3)

A plurality of laser light sources that emit laser beams of different wavelengths;
A plurality of first temperature control elements that are provided corresponding to the plurality of laser light sources and control the temperature of the laser light sources;
An optical transmission unit for transmitting laser light emitted from the plurality of laser light sources;
A multiplexing unit that multiplexes the laser beams from the plurality of laser light sources that have exited the light transmission unit, emits them to an optical fiber, and branches a part of the laser beams from the plurality of laser light sources;
A second temperature control element for controlling the temperature of the multiplexing unit;
A plurality of photodetectors provided corresponding to the plurality of laser light sources and detecting a part of the laser beams of the plurality of laser light sources emitted from the multiplexing unit;
A control circuit for controlling the second temperature control element so that the laser output is controlled to a predetermined value based on the detection outputs of the plurality of photodetectors and the temperature of the combining unit is set to a predetermined temperature; The optical fiber output type multi-wavelength laser light source device, wherein the unit is thermally insulated from the plurality of laser light sources.   2. The optical fiber output type multi-wavelength laser light source apparatus according to claim 1, wherein each of the plurality of laser light sources is thermally insulated from each other. 2. The control circuit according to claim 1, wherein the control circuit controls the second temperature control element based on outputs of the plurality of photodetectors so that fluctuations in light output of the plurality of laser light sources become a predetermined value or less. An optical fiber output type multi-wavelength laser light source device according to claim 2.

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