Fig. 1. Classification and applications of optical phased array
Fig. 2. Principle of optical phased array (1D)
Fig. 3. Optical phased array projects carried out by DARPA
Fig. 4. Schematic diagram of APPLE system
Fig. 5. Prototype of Excalibur system
Fig. 6. Schematic diagram of solid-state slab lasers
Fig. 7. 5.2 kW all-fiber MOPA configuration
Fig. 8. 100 kW solid-state laser system by Northrop Grumman
Fig. 9. 107-channel fiber laser coherent combining system
Fig. 10. 4 kW fiber laser coherent beam combining by Lincoln Lab. MIT
Fig. 11. One-dimensional liquid crystal optical phased array by Raytheon
Fig. 12. Wide-angle 1D liquid crystal optical phased array by North Carolina State University
Fig. 13. 64-channel 180° waveguide optical phased array
Fig. 14. CMOS waveguide optical phased array by University of Southern California
Fig. 15. 7-channel coherent beam combining system by University of Dayton
Fig. 16. Experimental setup of 21-channel coherent beam combining system by University of Dayton
Fig. 17. 57-channel TIL system by Institute of Optics and Electronics
Fig. 18. MMT telescope system
Fig. 19. James Webb Space Telescope
| type | power | feature | compactness | applicability in OPA | | gas laser | ＞500 kW | extremely high power
large volume
| extremely low | × | | chemical laser | ＞MW | extremely high power
large volume
| extremely low | × | | solid-state laser | ＞100 kW | high power
compact structure
| high | √ | | fiber laser | ～10 kW | high power
flexible
| higher | √ | | semiconductor laser | ～100 W | highly compact
high efficiency
| extremely high | √ |
|
Table 1. Contrast of different laser sources
| year | type | institution | power/kW | beam quality | | 2009 | slab | Northrop Grumman , USA | 15.3 | 1.58 | | 2010 | slab | North China Research Institute of Electro-Optics, China | 11.0 | 4.8 | | 2011 | slab | China Academy of Engineering Physics, China | 11.3 | 7.56 | | 2012 | disk | Boeing, USA | 30.0 | ＜ 2 | | 2015 | disk | General Atomics, USA | 150.0 | | | 2018 | slab | China Academy of Engineering Physics, China | 22.3 | 3.3 | | 2018 | disk | China Academy of Engineering Physics, China | 9.8 | 14.7 | | 2019 | slab | Technical Institute of Physics and Chemistry, China | 60.0 | | | 2021 | waveguide | China Academy of Engineering Physics, China | 10.0 | ＜ 3 |
|
Table 2. Representative research results of solid-state lasers
| year | type | institution | power/kW | beam quality | | 2016 | monolithic fiber | Fujikura Ltd., Japan | 2 | 1.2 | | 2016 | National University of Defense Technology, China | 2 | 1.6 | | 2017 | Fujikura Ltd., Japan | 3 | 1.3 | | 2017 | National University of Defense Technology, China | 3.05 | 1.3 | | 2018 | Fujikura Ltd., Japan | 5 | 1.3 | | 2018 | National University of Defense Technology, China | 5.2 | 2.2 | | 2020 | Fujikura Ltd., Japan | 8 | | | 2020 | National University of Defense Technology, China | 7 | 2.4 | | 2021 | National University of Defense Technology, China | 6 | 1.3 | | 2015 | MOPA | National University of Defense Technology, China | 3.15 | 1.6 | | 2016 | Massachusetts Institute of Technology, USA | 3.1 | 1.15 | | 2017 | Tianjin University, China | 8.05 | 4 | | 2018 | China Academy of Engineering Physics, China | 11.23 | | | 2019 | Shanghai Institute of Optics and Fine Mechanics, China | 10.14 | | | 2021 | China Academy of Engineering Physics, China | 5.07 | 1.252 | | 2021 | | National University of Defense Technology, China | 6 | 1.36 |
|
Table 3. Representative research results of fiber lasers
| year | type | institution | power/kW | number of channels | | 2008 | solid-state laser | Northrop Grumman, USA | 30 | 2 | | 2009 | Northrop Grumman, USA | 100 (Record) | 8 | | 2011 | fiber laser | Thales Research & Technology, France | | 64 | | 2011 | National University of Defense Technology, China | 1.08 | 9 | | 2011 | Massachusetts Institute of Technology, USA | 4 | 8 | | 2011 | University of Dayton, USA | | 7 | | 2014 | Northrop Grumman, USA | 2.4 | 3 | | 2015 | Massachusetts Institute of Technology, USA | 44 | 42 | | 2016 | University of Dayton, USA | | 21 | | 2019 | National University of Defense Technology, China | | 60 | | 2019 | National University of Defense Technology, China | 8 | 7 | | 2020 | Thales Research & Technology, France | 0.105 | 61 | | 2020 | Civan Advanced Technologies, Israel | 16 | 37 | | 2020 | National University of Defense Technology, China | | 107 (record) |
|
Table 4. Representative research results of coherent beam combining
| type | maturity | feature | future trends | | liquid crystal OPA | high | mature fabrication technology
suitable for high-power application
| large aperture
high damage threshold
large range
| | waveguide OPA | low | compactness
large view field
high frequency
| more channels
larger view field
higher frequency
| | MEMS OPA | low | high efficiency
fast response
| more channels | | novel OPA | | flexible | more advantages integration |
|
Table 5. Contrast of optical phased arrays and corresponding development trend
| year | institute | number of channels | experimental environment | | 2011 | University of Dayton, USA | 7 | 7 km outdoor | | 2016 | 21 | 7 km outdoor | | 2012 | Institute of Optics and Electronics, China | 7 | 5 m in Lab. (without turbulence) | | 2018 | 7 | 0.2 km outdoor | | 2021 | 19 | 2 km outdoor | | 2021 | 51 | 2.1 km outdoor | | 2011 | National University of Defense Technology, China | 2 | 10 m in Lab.(without turbulence) | | 2012 | 9 | 10 m in Lab.(without turbulence) | | 2018 | 6 | 0.8 km outdoor |
|
Table 6. Representative research results of atmospheric distortion correction based on TIL
