[PDF] Top 20 Surface-emitting terahertz quantum cascade lasers with continuous-wave power in the tens of milliwatt range

... efficient surface-emitting terahertz frequency quantum cascade lasers with continuous wave output powers of 20–25 mW at 15 K and maximum operating temperatures of ... See full document

... owing to changes in the surface profile and morphology. We found experimentally that this effect could suddenly drive the QCL out of lock, thus compromising the image acquisi- tion. To limit the effect of this ... See full document

... In this letter, we present the detailed design, fabrication and experimental results of THz frequency CCG DFB QCLs. Robust single-mode operation is realized at all bias currents, and the side-mode suppression ratios were ... See full document

... of terahertz frequency quantum cascade la- sers for applications as local ...A range of active region designs and waveguide structures have been characterised in order to develop the devices ... See full document

... [1]. Terahertz QCLs are now able to source up to 1 W in pulsed mode [2] and operate at temperatures as high as 200 K in pulsed mode ...to continuous wave (cw), operation of THz QCLs makes it possible ... See full document

... output power measured for three of the devices, when driven by a continuous train of pulses of different duty-cycles at a repetition rate of 1 kHz and with a heat-sink temperature of ...the power is ... See full document

... resulting surface-emitting THz beam is highly collimated with a beam divergence as narrow as ,4 u 3 10 u ...THz power, away from the surface-emitting beam, implies a high coupling ... See full document

... ultra-low power consumption substrate-emitting distributed feedback (DFB) quantum cascade laser (QCL) was ...The continuous-wave (CW) threshold power dissipation is ... See full document

... Figure 3 shows the LI curve of a CCG DFB QCL com- pared with that of a ridge-waveguide laser of similar area. An increased output power, by a factor of approximately three times, is measured. Owing to the Stark ... See full document

... in continuous-wave (CW) mode (with a notable exception being [52], which employs a sophisticated scheme using a THz amplifier with a pulsed QCL) and hence requiring large electrical driving power ... See full document

... (THz) quantum cascade lasers (QCLs) have undergone rapid development since their demonstration, showing high power, broad-tunability, quantum-limited linewidth, and ultra-broadband ... See full document

... cade lasers with light emission at k ...output power and the slope efficiency are higher than those obtained with interband VCSEL devices 14,15 but still considerably lower than from edge-emitting ... See full document

... (315 GHz, 155 GHz, 115 GHz, and 80 GHz for cavity lengths of 125 lm, 255 lm, 350 lm, and 515 lm, respectively). In an effective mirror picture, this is produced by the etalon effect of the short cavity þ air gap, which ... See full document

... dynamic range can be achieved with cryogenically cooled bolometric ...dynamic range of 33 dB with a peak THz power of 4 mW, despite the QCL being driven with low duty cycle ...dynamic range ... See full document

... of quantum wells, superlattices, quantum-cascade lasers, and quantum-well infrared photodetectors from near- to far-infrared and terahertz spectral ...of ... See full document

... on power extraction and spectral ...optical power of ≈21 mW in pulsed mode, and up to ...the surface pattern distribution, we also demonstrated a new route for fi ne control of the spectral properties ... See full document

... liquid-helium continuous-flow cryostat equipped with ...average power was measured using an absolute terahertz power meter (Thomas Keating), which was butted against the cryostat ...output ... See full document

... doping. This asymmetric doping creates an electric field profile across the device, as previously described for graphene-based photodetectors operating at optical communications frequencies [5]. The detector was ... See full document

... The transmission images of the 26 vol % PETN pellet acquired at each frequency are shown in figure 7. The image size is 44  44 pixels, corresponding to an area measuring 11 mm  11 mm, and the images have been ... See full document

... the surface of a cone with the axis oriented along h ¼ 0 (a ¼ 90 ) with divergences of 50 (sample D) and 70 (sample E) corresponding to a m ¼ 65 and a m ¼ 55 ... See full document