Long-wavelength infrared (~10-15 mm) electroluminescence from Sb-based interband cascade devices.

Electroluminescence in the long-wavelength infrared (10-15 mm) spectrum region was observed from Sb-based type-II interband cascade quantum well structures. The device structure was grown by molecular beam epitaxy on a GaSb substrate and comprises 10 repeated periods of active regions separated by digitally graded multilayer injection regions. The devices have been operated at 300 K and 77 K, with an output optical power up to 50 nW. The emission wavelength, the longest observed in any compound semiconductor material at room temperature, results from tailoring the heterostructure, demonstrating a unique capability of this Sb-family type-II material system.

Field-effect-transistor self-electro-optic-effect-device (FET-SEED) electrically addressed differential modulator array.

We describe a 6 × 6 array of electrically addressed field-effect-transistor self-electro-optic-effect-device differential modulators in which each element has a single-stage amplifier to permit an input voltage of less than 1 V to control the output modulators, which can operate at as high as 10 V. The variations in the switching voltages across the array are less than ±70 mV, and the individual array elements are operated at as high as 2 Gbits/s. We also measure cross talk between adjacent elements within the array, measure the dependence of the switching time on the input voltage swing, and calculate the dependence of the switching time that is due to the photocurrent of the modulators.