Lucent Technologies Inc.

Raffaele Colombelli

Federico Capasso

Alfred Yi Cho

Deborah Lee Sivco

Claire F Gmachl

Arthur Mike Sergent

Oskar Jon Painter

Albert Lee Hutchinson

Alessandro Tredicucci

Donald M Tennant

Mariano Troccoli

Nina Owschimikow

Kartik Srinivasan

An optoelectronic transducer comprises a unipolar, intraband active region and a micro-cavity resonator. The resonator includes a 2D array of essentially equally spaced regions that exhibits resonant modes. Each of the spaced regions has a depth that extends through the active region and has an average refractive index that is different from that of the active region. The refractive index contrast, the spacing of the spaced regions, and the dimensions of the spaced regions are mutually adapted so that the array acts as a micro-cavity resonator and so that at least one frequency of the resonant modes of the array falls within the spectrum of an optoelectronic parameter of the active region (i.e., the gain spectrum where the transducer is a laser; the absorption spectrum where the transducer is a photodetector). In a first embodiment, the transducer is an ISB laser, whereas in a second embodiment it is a unipolar, intraband photodetector. In other embodiments, the laser is a surface-emitting ISB laser and the photodetector is a vertically-illuminated detector. In another embodiment, a nonlinear optical material is optically coupled to the micro-cavity resonator, which in one case allows an ISB laser to exhibit bistable operation.

Unipolar, intraband optoelectronic transducers with micro-cavity resonators

A monolithic apparatus has a laser optical cavity. The laser optical cavity has a multi-layer structure that includes a first active semiconductor multi-layer and a second semiconductor multi-layer. The second semiconductor multi-layer is located laterally adjacent to the first active semiconductor multi-layer. The first active semiconductor multi-layer includes a sequence of quantum well structures that produce light of a lasing frequency in response to being electrically pumped. The second semiconductor multi-layer includes a sequence of quantum well structures and is configured to both absorb light of the lasing frequency and produce one of parametric light and harmonic light in response to absorbing light of the lasing frequency.

Nonlinear semiconductor light sources

The measurement of intersubband electroluminescence (ISB-EL) in unipolar quantum cascade lasers is achieved by forming a longitudinal cleave through the active region and waveguide of the QC laser device, exposing a complete side face of the device, including the active region. The conventional laser facets at the entrance and exit of the active region are coated with a highly reflective material and the emission from the exposed side face is measured. In theory, the sideface emission would comprise only the ISB-EL spontaneous emission, but some additional laser emission (due to scattering in the imperfect waveguide structure) also exits along this sideface. Spatial filtering and/or polarization monitoring can be used to differentiate the laser emission from the ISB-EL spontaneous emission.

Technique for measuring intersubband electroluminescence in a quantum cascade laser

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Hoboken, NJ, United States of America

Raffaele Colombelli