High-power all-fiber mid-infrared laser
By using Raman fiber pumping and an all-fiber architecture to design a mid-infrared laser, the problems of heat, environmental sensitivity and integration limitations of existing mid-infrared high-power fiber lasers have been solved, achieving high-power, stable laser output and system robustness.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHENZHEN UNIV
- Filing Date
- 2025-01-23
- Publication Date
- 2026-07-30
AI Technical Summary
Existing mid-infrared high-power fiber lasers suffer from problems such as high quantum defect, significant heat generation, sensitivity to environmental factors, and limitations in integration, which restricts the improvement of laser performance.
A Raman fiber laser pump source with a frequency shift from 1.5μm to 1.7μm is used. Combined with an all-fiber architecture design, low-doped fiber is used to reduce heat generation. Through pump power combining and power amplification technology, an all-fiber system is constructed to avoid space optical components and enhance system stability.
It achieves high-power, stable laser output, breaks through the power limit of a single oscillator, improves the robustness and anti-interference ability of the system, simplifies maintenance operations, and is suitable for various environments.
Smart Images
Figure CN2025074399_30072026_PF_FP_ABST
Abstract
Claims
1. A high-power all-fiber mid-infrared laser, characterized in that, The system includes a Raman fiber laser pump source, a fiber laser system, a fiber-coupled pump power stripper and a fiber-coupled isolator, and an all-fiber laser amplification system. The Raman fiber laser pump source generates a 1.7μm pump light from a 1.5μm laser through Raman effect frequency shifting. The fiber laser system absorbs the 1.7μm pump light to generate a 2.8μm mid-infrared laser. The laser amplification system amplifies the 2.8μm laser to generate a high-power mid-infrared laser. A 2.8μm fiber-coupled pump power stripper and isolator are implemented based on a fluoride fiber lens. A multi-pumped mid-infrared single-mode fiber pump combiner is implemented based on a quartz / fluoride fiber. The above systems are connected through fiber optic devices to construct an all-fiber high-power mid-infrared laser.
2. The high-power all-fiber mid-infrared laser as described in claim 1, characterized in that, The Raman fiber laser pump source includes multiple 1.7μm fiber lasers, which are input into the gain fiber cladding through a combiner; the pump source is a Raman fiber laser pump source, which is frequency-shifted from 1.5μm to 1.7μm through the Raman effect; the combiner is a single-mode fluoride / quartz fiber single-mode pump combiner.
3. The high-power all-fiber mid-infrared laser as described in claim 2, characterized in that, The 1.7μm pump light is absorbed by the fiber gain medium to generate 2.8μm spontaneous emission light. The spontaneous emission light is continuously reflected by the fiber Bragg grating and amplified by stimulated emission to achieve laser output in the 2.8μm band.
4. The high-power all-fiber mid-infrared laser as described in claim 3, characterized in that, The fiber gain medium is composed of rare-earth ion-doped fluoride fiber gain material, which has high transmittance to mid-infrared lasers.
5. The high-power all-fiber mid-infrared laser as described in claim 4, characterized in that, The reflection peak of the fiber Bragg grating is located at 2.8 μm; the fiber Bragg grating is written on the core of the gain fiber using a femtosecond laser direct writing method.
6. The high-power all-fiber mid-infrared laser as described in claim 5, characterized in that, The 20mm region around the 2.8μm fiber Bragg grating is actively cooled by a thermoelectric cooler.
7. The high-power all-fiber mid-infrared laser as described in claim 6, characterized in that, The output end of the high-power all-fiber mid-infrared laser is equipped with a fiber power stripper; the fiber cap at the output end of the high-power all-fiber mid-infrared laser is cut at an angle.
8. The high-power all-fiber mid-infrared laser as described in claim 1, characterized in that, The heat dissipation system of the high-power all-fiber mid-infrared laser is achieved by using an aluminum water-cooled plate with a water-cooling temperature set at 15°C.
9. The high-power all-fiber mid-infrared laser as described in claim 8, characterized in that, The high-power all-fiber mid-infrared laser adopts the MOPA system. The low-power laser output from the seed laser source is transmitted through a pump power stripper and an optical fiber isolator. It is amplified step by step by a preamplifier and a main amplifier. The seed laser source uses a pump power stripper to filter the 1.7μm laser. The pump power stripper is composed of a fluoride fiber lens and a dichroic mirror. The fiber lens is made by grinding the end face of the fiber into a spherical surface.
10. The high-power all-fiber mid-infrared laser as described in claim 9, characterized in that, The fiber optic isolator in the MOPA system uses a mid-infrared fiber optic isolator. The isolator provides beam collimation and isolates reflected light through the Faraday effect. The isolator consists of a fluoride fiber optic lens and a magneto-optical crystal. The fiber optic lens is formed by grinding the end face of the fiber into a spherical surface.