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.

Formation of laterally ordered single InAs quantum dot (QD) arrays by self-organized anisotropic strain engineering of InGaAs/GaAs superlattice templates on GaAs (311)B by molecular beam epitaxy is achieved through optimization of growth temperature, InAs amount, and annealing. Directed self-organization of these QD arrays is accomplished by coarse substrate patterns providing absolute QD position control over large areas. Due to the absence of one-to-one pattern definition the site-controlled QD arrays exhibit excellent optical properties revealed by resolution limited (80 μeV) linewidth of the low-temperature photoluminescence from individual QDs.

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Self-organized anisotropic strain engineering guided on shallow- and deep-patterned GaAs (311)B substrates is exploited for formation of complex laterally ordered architectures of connected InGaAs quantum dot (QD) arrays and isolated InAs QD groups by molecular beam epitaxy. The combination of strain and step engineerings on shallow stripe-patterned substrates transforms the periodic spotlike arrangement of the InGaAs QD arrays and InAs QD groups (on planar substrates) into a zigzag arrangement of periodic stripes which are well ordered over macroscopic areas on zigzag mesa-patterned substrates. In contrast, the formation of slow-growing facets on deep-patterned substrates produces QD-free mesa sidewalls, while InGaAs QD arrays and InAs QD groups form on the GaAs (311)B top and bottom planes with arrangements modified only close to the sidewalls depending on the sidewall orientation. The QDs on the shallow- and deep-patterned substrates exhibit excellent optical properties up to room temperature. Therefore, the concept of guided self-organization demonstrated on shallow-patterned (due to steps) and deep-patterned (due to facets) substrates is highlighted for creation of complex architectures of laterally ordered QDs for future quantum functional devices.