Lasing Characteristics of Low-Threshold GaInNAs Lasers Grown by Metalorganic Chemical Vapor Deposition

Abstract

We report on the lasing characteristics of low-threshold long-wavelength GaInNAs double quantum well (DQW) lasers grown by metalorganic chemical vapor deposition (MOCVD). We have achieved a threshold current density of 450 A/cm2 for a 1.28-µm-emitting laser. This is the lowest value for 1.3-µm-range GaInNAs lasers grown by MOCVD. We also observed high characteristic temperatures (T 0) of 210 K and 130 K for 1.25 µm and 1.28 µm lasers, respectively. In addition, we investigated the gradual change in lasing characteristics under pulsed operation. The blue shift of an emission wavelength and a threshold current reduction were observed, which is similar to that observed in the thermal annealing of GaInNAs.

Low-threshold-current-density 1300-nm dilute-nitride quantum well lasers

“…To the best of our knowledge, these data represent the lowest threshold-and transparencycurrent densities reported for InGaAsN QW lasers in the wavelength regime of 1.28 -1.32 m as shown in Table I. [1][2][3][4][5][6][7][8][9][10][11][12] The external differential quantum efficiency ( d ) of the InGaAsN QW lasers, as shown in Fig. 3, is as high as 57% for devices with cavity lengths of 720 m. The lower d for the longer cavity devices is attributed to the relatively large internal loss (␣ i ϭ13 cm 1 ) for these unoptimized structures.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Less temperature sensitivity in InGaAsN QW lasers, at ϭ1300 nm, has also been demonstrated in many of the published results. [1][2][3][4][5][6][7][8][9][10][11][12] Although the area of temperature sensitivity in InGaAsN QW lasers is still under extensive investigation, 13,14 promising results of both low threshold-current-density (J th ) and high T 0 values ͓1/T 0 ϭ(1/J th )dJ th /dT͔ have been demonstrated. 3,6,12 Recently, efforts to achieve high performance InGaAsN QW lasers by metalorganic chemical vapor deposition ͑MOCVD͒ 3-7 have been pursued.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Although the area of temperature sensitivity in InGaAsN QW lasers is still under extensive investigation, 13,14 promising results of both low threshold-current-density (J th ) and high T 0 values ͓1/T 0 ϭ(1/J th )dJ th /dT͔ have been demonstrated. 3,6,12 Recently, efforts to achieve high performance InGaAsN QW lasers by metalorganic chemical vapor deposition ͑MOCVD͒ 3-7 have been pursued. The advantage of the MOCVD-grown InGaAsN QW lasers is the ease in growing high quality AlAs/GaAs distributed Bragg reflectors by MOCVD, compared to molecular beam epitaxy ͑MBE͒ techniques, for realizing low-cost VCSELs.…”

“…The advantage of the MOCVD-grown InGaAsN QW lasers is the ease in growing high quality AlAs/GaAs distributed Bragg reflectors by MOCVD, compared to molecular beam epitaxy ͑MBE͒ techniques, for realizing low-cost VCSELs. Only recently, MOCVD-grown InGaAsN QW lasers, [3][4][5][6][7] at ϭ1300 nm, have demonstrated comparable performances with the MBEgrown InGaAsN QW lasers. [8][9][10][11][12] As shown in our earlier studies, 3 tensile-strained buffer layers ͑InGaPϩGaAsP͒ are crucial for achieving highly strained InGaAs͑N͒ QW lasers grown on thick, highAl-content ͑75%-85%͒ AlGaAs lower cladding layers.…”

“…These challenges have resulted in difficulties in realizing high performance MOCVD-InGaAsN QW lasers with AsH 3 as the As precursor until recently. 3,4,6,7 In our approach, the design of the active region is based on strain-compensated InGaAsN QW, with very high In content ͑Inϳ40%͒ and minimum N content ͑Nϳ0.5%͒, to achieve 1300-nm emission. Minimum N content in the InGaAsN QW allows us to grow the active region with an optimized AsH 3 /III ratio.…”