Low-threshold interband cascade lasers with power efficiency exceeding 9%

Abstract

Midinfrared (3.6–3.8 μm) interband cascade lasers based on InAs/GaInSb type-II quantum wells have been demonstrated in the continuous-wave (cw) mode with low-threshold current densities (e.g., ∼56 A/cm2 at 80 K) and power efficiencies exceeding 9%. At a relatively low current of 0.4 A, we observed ∼100 mW/facet of optical power out at 80 K (124 mW at 60 K) from lasers mounted epilayer-side up with uncoated facets. These lasers were able to operate in the cw mode at temperatures up to 127 K. Also, in the pulsed mode, devices lased at temperatures up to 250 K and displayed, at 80 K, a peak power efficiency exceeding 11%.

The Interband Cascade Laser

“…They soon improved the low-temperature EDQE per stage to ≈ 20% (> 4.5 photons emitted from all the stages for every electron injected into the device) at T = 150 K [34], although high-temperature operation was still elusive because the threshold power density remained high. Like the other early ICLs, these structures had 20-25 active stages that required a high threshold voltage approaching 10 V. Pulsed operation was observed at temperatures up to 217 K [35,36], and later 250 K [37]. Cw lasing was also achieved at temperatures up to 142 K [38,39].…”

Mid-IR interband cascade lasers: progress toward high performance

“…The lasing wavelengths range from ~3.66 to 3.73 µm, depending on the current and temperature, red shifting substantially with increasing device temperature. Threshold current densities of ~39, 56, 88, and 164 A/cm 2 were observed from a 60-µm-wide and 1.08 mm-long mesa stripe laser at 60, 80, 100, and 120 K, respectively, which are the lowest ever reported among diode lasers at this wavelength [17]. With a short cavity (0.53 µm), a cw optical output power of ~ 95 mW was observed from one facet of a 60-µm-wide deepwet-etched mesa-stripe laser at 60 K and at a current of 200 mA as shown in Fig.…”

“…Hence, a type-II IC laser can deliver considerable power at a low current in contrast to other types of mid-IR diode lasers. Combining a very efficient use of applied bias voltage in cascade structures [2,[14][15][16][17][18], power efficiencies exceeding 12% were obtained from this device at 60 and 80 K. x 100…”

“…A review of early work on type-II IC emitters is given in Ref. 14. Recently, significant advances [15][16][17][18] have been made by us at ARL in the development of type-II IC lasers in terms of record-high differential quantum efficiency, peak output power, operating temperature, continuous wave (cw) operation, power conversion efficiency, and reproducibility. Here, we review our recent progress and present some updated results along with discussions of these IC lasers.…”

Multi-Wavelength Mid-Infrared Micro-Spectral Imaging Using Semiconductor Lasers

“…A much higher power laser can take a snap shot of an entire sample without scanning. Recent advances in MIR semiconductor laser technology such as Sb lasers [17][18][19][20][21][22] and quantum cascade lasers 2 3 -2 7 offer orders-of-m agnitude im provem ent in power and brightness. Many applications of lead-salt laser spectroscopy such as gas sensing have gradually shifted to the use of these m odern lasers when high power and brightness are desired.…”