Widely separate wavelength switching of single quantum well laser diode by injection-current control

Capasso²,

et al. 2001

SPIE Proceedings

A new scheme for generation of coherent radiation on the intersubband transition without population inversion between subbands is presented. The scheme is based on the resonant nonlinear mixing of the optical laser fields on the two interband transitions that are generated in the same active region and serve as a coherent drive for the infrared field. The two-wavelength lasing on the interband transitions can be achieved at substantially lower threshold current than population inversion and gain on the intersubband transition. This may ensure stable highpower room-temperature operation. Due to parametric, inversionless nature of generation, the proposed lasers are especially promising for the long-wavelength operation above 20 micron.

Section: Generic Three-level Schemementioning

confidence: 99%

<title>Two-color heterolasers as parametric generators of infrared radiation</title>

Capasso²,

et al. 2001

SPIE Proceedings

“…Upon increasing the pumping current, optical generation can start also from excited states and the laser can be completely switched to lasing from the excited state which has higher maximum gain due to a larger density of states. The effect of excited-state lasing was studied both in QW and QD lasers [5][6][7]. It was found that with optimized laser parameters the region of simultaneous ground-state and excited-state lasing can be around j -2 Jth [5,6].…”

Section: Generic Three-level Schemementioning

confidence: 99%

“…The effect of excited-state lasing was studied both in QW and QD lasers [5][6][7]. It was found that with optimized laser parameters the region of simultaneous ground-state and excited-state lasing can be around j -2 Jth [5,6].…”

Section: Generic Three-level Schemementioning

confidence: 99%

Resonant parametric generation of infrared radiation on intersubband transitions in low-dimensional semiconductor heterostructures

Capasso²,

et al. 2001

Nanotechnology

Abstract.A new scheme for generation of coherent radiation on the intersubband transition without population inversion between subbands is presented. The scheme is based on the resonant nonlinear mixing of the optical laser fields on the two interband transitions which are generated in the same active region and serve as a coherent drive for the infrared field. This mechanism for frequency self-conversion can work efficiently at room temperature and with injection current pumping. Due to the parametric nature of infrared generation, the proposed inversionless scheme is especially promising for long-wavelength (far-infrared) operation.

“…Upon increasing the pumping current, optical generation can start also from excited states and the laser can be completely switched to lasing from the excited-state which has higher maximum gain due to a larger density of states. The effect of excited-state lasing was studied both in QW and QD lasers [4,[11][12][13]. It was found that with optimized laser parameters the region of simultaneous ground-state and excited-state lasing can be around j ∼ 2j th [12,13].…”

mentioning

confidence: 99%

“…The effect of excited-state lasing was studied both in QW and QD lasers [4,[11][12][13]. It was found that with optimized laser parameters the region of simultaneous ground-state and excited-state lasing can be around j ∼ 2j th [12,13]. In order to have the region of twowavelength lasing sufficiently broad (∆j ∼ (0.1−0.2)j th ), gains for the two wavelengths should be close to each other.…”

mentioning

confidence: 99%

Infrared generation in low-dimensional semiconductor heterostructures via quantum coherence

Capasso²,

et al. 2001

Phys. Rev. A

A new scheme for infrared generation without population inversion between subbands in quantumwell and quantum-dot lasers is presented and documented by detailed calculations. The scheme is based on the simultaneous generation at three frequencies: optical lasing at the two interband transitions which take place simultaneously, in the same active region, and serve as the coherent drive for the IR field. This mechanism for frequency down-conversion does not rely upon any ad hoc assumptions of long-lived coherences in the semiconductor active medium. And it should work efficiently at room temperature with injection current pumping. For optimized waveguide and cavity parameters, the intrinsic efficiency of the down-conversion process can reach the limiting quantum value corresponding to one infrared photon per one optical photon. Due to the parametric nature of IR generation, the proposed inversionless scheme is especially promising for long-wavelength (farinfrared) operation.