Terahertz quantum cascade lasers

  title={Terahertz quantum cascade lasers},
  author={Benjamin S. Williams},
  journal={2008 Asia Optical Fiber Communication \& Optoelectronic Exposition \& Conference},
  • B. Williams
  • Published 1 September 2007
  • Physics
  • 2008 Asia Optical Fiber Communication & Optoelectronic Exposition & Conference
An overview of terahertz quantum cascade lasers based on resonant-phonon depopulation is presented. Limiting mechanisms for high-temperature operation are discussed. 

Laser Level Selection in Terahertz Quantum Cascade Lasers

The active region of a terahertz quantum cascade laser with two optical transitions is studied. The population of upper laser states, which correspond to 3.4 and 3.8 THz, are investigated at

High-power THz quantum cascade lasers

High power terahertz quantum cascade lasers with symmetric, wafer bonded active regions are presented, which are ideally suited for object illumination for real-time terahertz imaging using a

Terahertz time domain spectroscopy of phonon-depopulation based quantum cascade lasers

A 3.1THz phonon depopulation-based quantum-cascade-laser is investigated using terahertz time domain spectroscopy. A gain of 25cm-1 and absorption features due to the lower laser level being

Terahertz quantum cascade lasers with symmetric active regions

We present terahertz quantum cascade lasers based on symmetric active regions. Polarity dependent performance differences are observed in the GaAs/AlGaAs and the InGaAs/GaAsSb system. The

Terahertz silicon lasers

  • H. HubersS. PavlovV. Shastin
  • Physics
    2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference
  • 2006
Terahertz silicon lasers are based on intracenter transitions of group-V donors. The peculiarities due to electron-phonon interaction and the state-of-the-art performance such as frequency tunability

Towards watt-level performance of terahertz quantum cascade lasers

Terahertz quantum cascade lasers have not reached watt-level output powers yet. We present surface-plasmon devices with a peak power of 0.94 W. The device consists of two symmetric active regions

Calculations of terahertz quantum cascade lasers with ternary compound semiconductor wells

We investigated performance of THz-QCLs with AlGaAs wells using NEGF method. Improvement due to decrease of GaAs-like LO phonons for high aluminum composition does not exceed degradation due to

High power terahertz quantum cascade laser at 63 µm

We present a terahertz quantum cascade laser providing 875 mW two-facet output power in pulsed mode, at a frequency around 4.7 THz and at a heatsink temperature of 10 K. The laser has a single

Programmable, Transform-Limited Pulses from a Terahertz Quantum Cascade Laser

We report programmable control of pulses from a quantum cascade laser. A programmable arbitrary waveform generator is used to control the emission of the lasers by gain-switching. Quantum cascade l...

Gain studies of phonon-depopulation based terahertz quantum cascade lasers using terahertz time domain spectroscopy

Gain and losses in a LO-phonon THz QCL are studied using TDS. At threshold the gain clamps at 25cm−1 and the gain FWHM is 0.6THz. At low biases, absorption features are observed below and above the



High-power terahertz quantum cascade lasers

We report the demonstration of quantum-cascade lasers at ~4.4 THz (lambda ~ 68 mum) that emit 248 mW peak power in pulsed mode, and 138 mW continuous-wave power at heat-sink temperatures of 10 K.

Horn antennas for terahertz quantum cascade lasers

Far-field pattern and extraction efficiency of double metal 1.8 THz quantum cascade lasers (QCL) are controlled using miniaturised horn antennas. Enhancement of the optical output power of ten times

Far infrared quantum-cascade lasers based on a bound-to-continuum transition

Laser emission at about 3.5 THz from quantum cascade lasers based on a bound-to-continuum transition is reported. Maximum pulsed operation temperature is above liquid nitrogen (90 K). CW operation

Terahertz quantum-cascade lasers based on a three-well active module

The authors report on a design of terahertz quantum-cascade lasers based on three-well active modules. Each module consists of two tunnel-coupled wells for the two lasing states and another well for

Linewidth and tuning characteristics of terahertz quantum cascade lasers.

The spectral linewidths of three continuous-wave quantum cascade lasers operating at terahertz frequencies are measured by heterodyning the free-running quantum cascade laser with two far-infrared gas lasers using a GaAs diode mixer and a microwave spectrum analyzer.

Ultra low threshold current THz quantum cascade lasers based on buried strip-waveguides

THz quantum cascade lasers based on a novel buried cavity geometry are demonstrated by combining double-metal waveguides with proton im plantation. Devices are realised with emission at 2.8 THz,

Terahertz quantum cascade lasers with copper metal-metal waveguides operating up to 178 K.

The improvement in the maximum operating temperature is achieved by using a three-quantum-well active region design with resonant-phonon depopulation and by utilizing copper, instead of gold, for the cladding material in the metal-metal waveguides.

Terahertz microcavity quantum-cascade lasers

We demonstrate circular-shaped microcavity quantum-cascade lasers emitting in the THz region between 3.0 and 3.8 THz. The band structure design of the GaAs∕Al0.15Ga0.85As heterostructure is based on

Low-threshold terahertz quantum-cascade lasers

A quantum-cascade laser operating at λ=66 μm is demonstrated. It consists of a three-quantum-well chirped-superlattice active region embedded in a waveguide based on a single interface plasmon and a

Low frequency terahertz quantum cascade laser operating from 1.6to1.8THz

The authors report a GaAs∕Al0.1Ga0.9As quantum cascade laser based on a bound-to-continuum transition optimized for low frequency operation. High tunability of the gain curve is achieved by the Stark