Table 1.

Recent achievements in HCSELs.

Year	Institution	Band	Output Power	Slope Efficiency	Divergence Angle	Structure	Ref
2005	University of Wisconsin	980 nm	20 units form an array: 1.6 W (continuous wave (C.W.))			Linear second-order grating	[29]
2006	BinOptics Corporation	1.3 μm	30 mW	~0.3 W/A	15° × 36°	mirror-type HCSEL	[28]
2012	Alfalight Company	97x nm	68 W (C.W.)	0.8 W/A	<8°	curved second-order grating	[30]
2014	Kyoto University	941 nm	1.5 W (C.W.)	0.66 W/A	<3°	Photonic crystals	[31]
2016	Taiwan National Chiao Tung University	1.3 μm	2 mW		1° × 8~9°	Linear second-order grating	[32]
2016	Institute of Semiconductors of the Chinese Academy of Sciences	7 μm	2.29 W	500 mW/A	2.9° × 0.36°	Linear second-order grating	[33]
2017	Institute of Semiconductors of the Chinese Academy of Sciences	4.97 μm	248 mW		0.14° × 16°	Linear second-order grating	[34]
2018	Lehigh University	3.4 THz	170 mW	993 mW/A	5° × 25°	Linear high-order grating	[35]
2018	Kyoto University	940 nm	7 W (C.W.)	0.48 W/A	<0.4°	Double lattice	[36]
2019	Changchun Institute of Optics, Fine Mechanics and Physics	1.3 μm	13.3 mW (C.W.)	40.9 mW/A		Quantum-dot Photonic-crystals	[37]
2019	Northwestern University	4.9 μm	6.7 W (peak power)			mirror-type HCSEL	[38]
2021	Changchun University of Science and Technology	976 nm	84 mW		2.6° × 6.1°	Linear second-order grating	[39]
2021	Kyoto University	940 nm	29 W (C.W.)	~0.66 W/A	<0.4°	Double lattice	[40]