Metalorganic chemical vapor deposition-grown In 0.4 Ga 0.6 As 0.995 N 0.005 quantum well ͑QW͒ lasers have been realized, at an emission wavelength of 1.295 m, with threshold and transparency current densities as low as 211 A/cm 2 ͑for Lϭ2000 m͒ and 75 A/cm 2 , respectively. The utilization of a tensile-strained GaAs 0.67 P 0.33 buffer layer and GaAs 0.85 P 0.15 barrier layers allows a highly-compressively-strained In 0.4 Ga 0.6 As 0.995 N 0.005 QW to be grown on a high-Al-content lower cladding layer, resulting in devices with high current injection efficiency ( inj ϳ97%͒. © 2002 American Institute of Physics. ͓DOI: 10.1063/1.1511290͔The dilute-nitride quantum well ͑QW͒ on GaAs substrate, to achieve 1300-nm wavelength emission, has been a very promising choice active region in realizing highperformance long-wavelength GaAs-based vertical cavity surface emitting lasers ͑VCSELs͒. 1-12 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. 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, 3-7 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. In the present work, we report very low threshold (J th )-and transparency (J th )-current-density, strain-compensated In 0.4 Ga 0.6 As 0.995 N 0.005 QW lasers with high current injection efficiency ( inj ) by utilizing strain compensation from GaAsP tensile-strained barriers and a thin GaAsP tensilestrained buffer layer.The lasers structures utilized here were all grown by low-pressure MOCVD. Trimethylgallium, trimethylaluminium, and trimethylindium are used as the group III sources and AsH 3 , PH 3 , and U-dimethylhydrazine ͑U-DMHy͒ are used as the group V sources. The dopant sources are SiH 4 and dielthylzinc for the n-and p-dopants, respectively. The laser structure, shown in Fig. 1, utilizes min. This annealing condition does not represent the optimized annealing temperature and duration for the InGaAsN QW, yet this condition is sufficient for achieving strong luminescence from the QW. The InGaAsN QW is surrounded by tensile-strain barriers of GaAs 0.85 P 0.15 (⌬a/aϭ0.6%͒, which are spaced 100 Å on ...

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The concept of below-threshold and above-threshold current injection efficiency of quantum well ͑QW͒ lasers is clarified. The analysis presented here is applied to the current injection efficiency of 1200 nm emitting InGaAs and 1300 nm emitting InGaAsN QW lasers. The role of heavy-hole leakage in the InGaAsN QW lasers is shown to be significant in determining the device temperature sensitivity. The current injection efficiency of QW lasers with large monomolecular recombination processes is shown to be less temperature sensitive. Excellent agreement between theory and experiment is obtained for both the 1200 nm emitting InGaAs QW and the 1300 nm emitting InGaAsN QW lasers. Suppression of thermionic carrier escape processes in the InGaAsN QW results in high performance 1300 nm emitting lasers operating up to high temperature.

The mid-infrared spectral region, 2-20 μm, is of great interest for sensing and detection applications, in part because the vibrational transition energies of numerous molecules fall in that region. Silicon photonics is a promising technology to address many of these applications on a single integrated, low-cost platform. Near-infrared light sources, heterogeneously integrated on silicon, have existed for more than a decade, and there have been numerous incorporations of mid-infrared optical devices on silicon platforms. However, no lasers fully integrated onto silicon have previously been demonstrated for wavelengths longer than 2.0 μm. Here we report, to the best of our knowledge, the first quantum cascade lasers on silicon emitting 4.8 μm light, integrated with silicon-on-nitride-on-insulator (SONOI) waveguides, and operating in pulsed mode at room temperature. The broadband and versatile nature of both quantum cascade lasers and the SONOI platform suggests that this development can be expanded to build photonic integrated circuits throughout the near-and mid-infrared on the same chip.

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