Tunable narrow-linewidth single-frequency linear-polarization laser device

Patent metadata

Field	Value
Publication number	US-9787050-B2
Application number	US-201415035605-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Jan 17, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A tunable narrow-linewidth single-frequency linear-polarization laser device comprising a heat sink, a pumping source packaged on the heat sink, a first and second collimating lenses, a laser back cavity mirror, a thermal optical tunable filter, a rare-earth-ion heavily-doped multicomponent glass optical fiber, a super-structure polarization-maintaining fiber grating, a polarization-maintaining optical isolator, a polarization-maintaining optical fiber, and a thermoelectric refrigerating machine. The laser device uses a short and straight single-frequency resonant cavity structure, the heavily-doped and high-gain characteristics of the multicomponent glass optical fiber, a frequency selection role and wavelength tuning function of the thermal optical tunable filter and the superstructure polarization-maintaining fiber grating, and combines a precision temperature adjustment technology, and by means of real-time adjustment of distribution of reflection wavelengths and transmission wavelengths, the laser device changes spectrum peak overlapping positions, so as to implement stable output of wide-tuning-range, extra-narrow-linewidth, high-extinction-ratio and high-output-power continuously tunable single-frequency linear-polarization laser.

First claim

What is claimed:

1. A tunable narrow-linewidth single-frequency linear-polarization laser device, characterized in that, comprising: a heat sink, a pumping source packaged on the heat sink, a first collimating lens, a laser back cavity mirror, a thermal optical tunable filter, a second collimating lens, a rare-earth-ion heavily-doped multicomponent glass optical fiber, a super-structure polarization-maintaining fiber grating, a polarization-maintaining optical isolator, a polarization-maintaining optical fiber, and a plurality of thermoelectric coolers (TECs); wherein the pumping source, the first collimating lens, the laser back cavity mirror, the thermal optical tunable fiber, the second collimating lens, the rare-earth-ion heavily-doped multicomponent glass optical fiber, the super-structure polarization-maintaining fiber grating, the polarization-maintaining optical isolator, the polarization-maintaining optical fiber being arranged in the listed order, and the pumping source, the thermal optical tunable filter and the super-structure polarization-maintaining fiber grating each being arranged on a respective thermoelectric cooler TEC).

2. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the output of the pumping source being coupled with the laser back cavity mirror via the first collimating lens, the laser back cavity mirror being coupled with the thermal optical tunable filter, the thermal optical tunable filter being coupled with the second collimating lens, the second collimating lens being coupled with the input of the rare-earth-ion heavily-doped multicomponent glass optical fiber, the output of the rare-earth-ion heavily-doped multicomponent glass optical fiber being coupled with the input of the super-structure polarization-maintaining fiber grating, the output of the super-structure polarization-maintaining fiber grating being coupled with the input of the polarization-maintaining optical fiber, the output of the polarization-maintaining optical fiber being coupled with a tail end of the polarization-maintaining optical fiber.

3. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the laser back cavity mirror being coated with a thin membrane layer on its mirror terminal surface, the thin membrane layer highly reflecting the laser signal wavelengths more than 80% and highly transmitting the pumping source wavelengths more than 80%.

4. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the thermal optical tunable filter being a Fabry-Perot type membrane tunable filter; the filter's respective thermoelectric cooler (TEC) performing precise temperature control and the thermal optical characteristics and the high refraction ratio of an intermediate membrane material of the filter being used, such that the B refraction ratio of the intermediate membrane material of the filter being varied to tune the output wavelength.

5. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein a fiber core component of the rare-earth-ion heavily-doped multicomponent glass optical fiber being 65P 2 O 5 -10Al 2 O 3 -20BaO-3La 2 O 3 -2Nd 2 O 3 ; the fiber core of the rare-earth-ion heavily-doped multicomponent glass optical fiber are evenly doped with high concentration of rare earth luminescence ions, the doping concentration of the rare earth luminescence ions being more than 1×10 20 ions/cm 3 ; the rare earth luminescence ions including one or more of lanthanide ions, alkaline earth metal ions, transition metal ions or their combinations.

6. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the shape of a fiber core of the rare-earth-ion heavily-doped multicomponent glass optical fiber being circular with a fiber core diameter of 3˜50 μm; the shape of a wrapping layer being circular, D-shaped, hexagon, or octagon, wherein the diameter of the circular wrapping layer or the side-to-side distance of the non-circular wrapping layer being 80˜900 μm.

7. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein one end of the rare-earth-ion heavily-doped multicomponent glass optical fiber being coated with a multi-layer antireflection coating, wherein the multi-layer antireflection coating highly transmitting the laser signal wavelengths with a transmission ratio of more than 90% to suppress the reflection of the fiber terminal surface.

8. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the super-structure polarization-maintaining fiber grating selectively comb reflecting the laser signal wavelengths which is partial transmission with a reflection ratio of the center wavelength being 20%˜80%, having a characteristic of uniformity of the reflection peaks and a narrow bandwidth as a coupling component for laser output.

9. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the pumping source being a semiconductor laser device with an edge emitting structure or other form of package; wherein the output mode of the pumping source being either single-mode or multi-mode, the outputting parameters of the pumping wavelength being 800˜1200 nm and the outputting pumping source being more than 50 mW; the pumping mode of the pumping source being forward pumping, that is, the pumping light emitted from the pumping source coupling directly through the collimating lens into the optical path.

10. The tunable narrow-linewidth single-frequency linear-polarization laser device according to claim 1 , wherein the temperature of the thermal optical tunable filter and the super-structure polarization-maintaining fiber grating being precisely controlled by independent thermoelectric coolers (TECs), constituting a section having the laser device wavelength/frequency tenability function; the precise temperature control causing the refraction ratio of the fiber grating and the filter vary accordingly such that the coupling overlapping positions of the reflection spectrum of the super-structure polarization-maintaining fiber grating and the transmission spectrum of the thermal optical tunable filter continuously varying to achieve an optical fiber frequency selection at different wavelengths, that is, to implement wide-tuning-range continuously tunable output wavelengths of the single-frequency linear-polarization laser device.

Assignees

• Univ South China Tech

Inventors

• Xu Shanhui
• Yang Changsheng
• Yang Zhongmin
• Feng Zhouming
• Zhang Qinyuan
• Jiang Zhonghong

Classifications

• H01S3/139

  by controlling the mutual position or the reflecting properties of the reflectors of the cavity {, e.g. by controlling the cavity length} · CPC title

• H01S3/06708

  Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering (optical fibres as passive waveguides G02B6/02) · CPC title

• H01S3/1028

  by controlling the temperature · CPC title

• H01S3/0401

  of optical elements being part of laser resonator, e.g. windows, mirrors, lenses · CPC title

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title