Dual-wavelength GaSb-based mid infrared photonic crystal surface emitting lasers

Abstract

We demonstrate dual-wavelength GaSb-based mid-infrared photonic crystal surface emitting lasers at room temperature. The two lasing peaks emitted simultaneously at 2.3 μm and 2.22 μm under optical pumping. Type-I InGaAsSb quantum wells were used for the active region. The photonic crystal with a rectangular lattice was fabricated on the surface to provide light coupling for laser operation. The two-wavelength operation was a result of the resonances from the two different grating periods along the two perpendicular directions of the rectangular lattice. The laser emissions from these two wavelengths were highly linearly polarized in two perpendicular directions as a result of the grating design.

Mid-Infrared Photonic-Crystal Surface-Emitting Lasers with InGaAs/GaAsSb ‘W’-Type Quantum Wells Grown on InP Substrate

“…The resonance shift of PC cavity dominates over bandgap shrinkage of 'W'-type QWs in temperature-dependent lasing wavelengths. It is worth it to mention that the temperature shift coefficients of cavity resonance and gain peak for GaSb-based type-I QW PCSELs in similar wavelength range were about 0.2 nm/K and 1.62 nm/K, respectively [10,13]. InP-based 'W'-type QW PCSELs exhibit cavity shift rate 15% lower and gain-peak shift rate about 30% lower than GaSb-based type-I QW PCSELs.…”

“…Moreover, the threshold pumping density is more sensitive to temperature change in InP-based 'W'-type QW PCSELs (To = 20-40 K) than in GaSb-based type-I QW PCSELs (To = 45-67 K, which was revealed in Ref. [13]).…”

“…As regards the RT-PL of GaSb-based type-I QW structure in Ref. [13], the spectral width at 98% intensity was 10 nm whereas the FWHM was about 121 nm. The flat-top feature in RT-PL is characteristic of InP-based 'W'-type QWs.…”

“…Gain media of InGaAs/GaAsSb 'W'-type QWs exhibit emission wavelength range of 2.2 μm. Moreover, lasing characteristics of MIR PCSELs of similar wavelength range are compared for both InP-and GaSb-based material systems [13].…”

Effect of Etching Depth on Threshold Characteristics of GaSb-Based Middle Infrared Photonic-Crystal Surface-Emitting Lasers

“…By properly designing two-dimensional (2D) photonic crystals (PhC) that satisfy a specific Bragg condition, light waves from gain media can couple with PhC, whereby a 2D cavity mode is constructed to produce lasing emissions from the surface of the device. GaSb-based PCSELs are designed in connection to the abovementioned TDLAS sensors; however, only optically pumped devices are successfully demonstrated [5,7], while electrically pumped ones are still in development [8].…”