Using the recently proposed shallow-well design, we demonstrate InP based quantum cascade lasers (QCLs) emitting around 4.9 μm with 27% and 21% wall plug efficiencies in room temperature (298 K) pulsed and continuous wave (cw) operations, respectively. The laser core consists of 40 QCL-stages. The highest cw efficiency is obtained from a buried-ridge device with a ridge width of 8 μm and a cavity length of 5 mm. The front and back facets are antireflection and high-reflection coated, respectively. The maximum single facet cw power at room temperature amounts to 5.1 W.

The authors report a room temperature operating InAs quantum-dot infrared photodetector grown on InP substrate. The self-assembled InAs quantum dots and the device structure were grown by low-pressure metal-organic chemical vapor deposition. The detectivity was 2.8×1011cmHz1∕2∕W at 120K and a bias of −5V with a peak detection wavelength around 4.1μm and a quantum efficiency of 35%. Due to the low dark current and high responsivity, a clear photoresponse has been observed at room temperature, which gives a detectivity of 6.7×107cmHz1∕2∕W.

We demonstrate quantum cascade lasers emitting at wavelengths of 3–3.2 μm in the InP-based material system. The laser core consists of GaInAs/AlInAs using strain balancing technique. In room temperature pulsed mode operation, threshold current densities of 1.66 kA/cm2 and 1.97 kA/cm2, and characteristic temperatures (T0) of 108 K and 102 K, are obtained for the devices emitting at 3.2 μm and 3 μm, respectively. Room temperature continuous wave operation is achieved at both wavelengths.

A dual-section, single-mode quantum cascade laser is demonstrated in continuous wave at room temperature with up to 114 nm (50 cm−1) of tuning near a wavelength of 4.8 μm. Power above 100 mW is demonstrated, with a mean side mode suppression ratio of 24 dB. By changing the grating period, 270 nm (120 cm−1) of gap-free electrical tuning for a single gain medium has been realized.

We report a high detectivity middle-wavelength infrared quantum dot infrared photodetector (QDIP). The InGaAs quantum dots were grown by self-assembly on an InGaP matrix via low pressure metalorganic chemical vapor deposition. Photoresponse was observed at temperatures above 200 K with a peak wavelength of 4.7 μm and cutoff wavelength of 5.2 μm. The background limited performance temperature was 140 K, and this was attributed to the super low dark current observed in this QDIP. A detectivity of 3.6×1010 cm Hz1/2/W, which is comparable to the state-of-the-art quantum well infrared photodetectors in a similar wavelength range, was obtained for this InGaAs/InGaP QDIP at both T=77 K and T=95 K at biases of −1.6 and −1.4 V, respectively.

We report a demonstration of an infrared focal plane array based on InGaAs/InGaP quantum dot infrared photodetectors. The middle-wavelength infrared quantum-dot infrared photodetector (QDIP) structure was grown via low-pressure metal organic chemical vapor deposition. A detectivity of 3.6×1010 cm Hz1/2/W was achieved at T=95 K and a bias of −1.4 V. The background limited temperature of our QDIP was 140 K with a 45° field of view. A 256×256 detector array was fabricated with dry etching, and hybridized to a Litton readout chip by indium bumps. Thermal imaging was achieved at temperatures up to 120 K. At T=77 K, the noise equivalent temperature difference was measured as 0.509 K with a 300 K background and f/2.3 optics.

This letter reports a 320×256 middle-wavelength infrared focal plane array operating at temperatures up to 200K based on an InAs quantum dot/InGaAs quantum well/InAlAs barrier detector grown on InP substrate by low pressure metal organic chemical vapor deposition. The device’s low dark current density and the persistence of the photocurrent up to room temperature enabled the high temperature imaging. The focal plane array had a peak detection wavelength of 4μm, a responsivity of 34mA∕W, a conversion efficiency of 1.1%, and a noise equivalent temperature difference of 344mK at an operating temperature of 120K.

Articles you may be interested inHigh power operation of λ5.2-11μm strain balanced quantum cascade lasers based on the same material composition Appl. Phys. Lett. 105, 071106 (2014); 10.1063/1.4893746 Watt level performance of quantum cascade lasers in room temperature continuous wave operation at λ 3.76 μ m Appl. Phys. Lett. 97, 131117 (2010); 10.1063/1.3496489 3 W continuous-wave room temperature single-facet emission from quantum cascade lasers based on nonresonant extraction design approach Appl. Phys. Lett. 95, 141113 (2009); 10.1063/1.3238263Above room-temperature operation of In As ∕ Al Ga Sb superlattice quantum cascade lasers emitting at 12 μ m Appl.An InP based quantum cascade laser ͑QCL͒ heterostructure emitting around 5 m is grown with gas-source molecular beam epitaxy. The QCL core design takes a shallow-well approach to maximize the characteristic temperatures, T 0 and T 1 , for operations above room temperature. A T 0 value of 383 K and a T 1 value of 645 K are obtained within a temperature range of 298-373 K. In room temperature continuous wave operation, this design gives a single facet output power of 3 W and a wall plug efficiency of 16% from a device with a cavity length of 5 mm and a ridge width of 8 m.