[PDF] Top 20 Terahertz sensing and imaging using a quantum cascade laser

... signal using an optical chopper, for this measurement the reflective plate was attached to a subwoofer speaker that was vibrated at ~20 Hz to generate a time-varying optical path ... See full document

... (THz) quantum cascade lasers (QCLs) [1] have stimulated significant interest in the development of imaging systems [2] at THz frequencies owing to their compact size, high output power (>1 W) [3] ... See full document

... Coherent imaging and sensing using the self-mixing effect in THz quantum cascade lasers Paul Dean, James Keeley, Alex Valavanis, Raed Alhathlool, Suraj P.. Khanna, Mohammad Lachab, Draga[r] ... See full document

... the quantum cascade laser (QCL) 1 has established itself as one of the most promising radiation sources for imaging applications 2–6 at terahertz (THz) fre- ...with quantum ... See full document

... of terahertz (THz) frequency imaging sys- tems based on quantum cascade lasers ...Incoherent imaging systems have been demonstrated using Golay cells, pyroelectric detectors, ... See full document

... sub-kilohertz quantum-noise-limited linewidths [36] and also offer potential for tunability ...of imaging capability compared to the broadband sources commonly used in TPI—namely: high source powers ... See full document

... of laser speckle and inhomogeneity within the ...measured using broadband THz time-domain spectroscopy [45] are also shown − these give good agreement with the values obtained using the THz ... See full document

... combined using a transform lens (f = 100 mm) and a diffraction grating (75 g/mm, ...the laser facet of 94 μm which is consistent with the 110-μm-wide output aperture of the tapered ...for laser #14, ... See full document

... the laser frequency through three external cavity resonances in the region where the laser was most sensitive to optical ...the laser ter- minals after 40 × gain (28dB) with a static ...acquired ... See full document

... coherent sensing scheme that employs a laser as a homodyne ...transceiver. Laser feedback interferometry relies on the remarkably universal SM effect — the sensitivity of a coherent source to its ... See full document

... of using slow-responding and/or cryogenic devices such as pyroelectric or Si-bolometer for detection, self-mixing is based on the perturbation introduced by the radiation scattered into the laser cavity by ... See full document

... Terahertz-frequency quantum cascade lasers (THz QCLs) have undergone steady development since their first demonstration in 2002 ...remote sensing and THz imaging [9, ... See full document

... The terahertz (THz) band is the part of electromagnetic spectrum located between photonics and electronics ...medical imaging applications ...a quantum cascade laser (QCL) [9, ...diode ... See full document

... Terahertz quantum cascade lasers (THz QCLs) are compact, electrically driven sources of radia- tion in the ∼ 1–5 THz band [1] that hold enormous potential for sensing [2,3] and communication ... See full document

... operation using e ffi cient cryo-coolers and also open up new applications (such as nonlinear optical studies) that require very high instantaneous THz ...LFI imaging application [20] compared with the use ... See full document

... Quantum cascade lasers (QCLs) are compact semiconductor sources of terahertz (THz) frequency radiation that are capable of emission powers of up to 1 W [1] and maximum operating temperatures of 200 K ... See full document

... are very similar. This results in the appearance of multiple lobes in the far-field pattern of the lasing mode [7], [8]. Whilst it may well be insignificant for certain applications (such as super heterodyne detection ... See full document

... femtosecond laser [20], and a femto- second laser comb [25] has been demonstrated, and very recently, the locking of a mid-IR QCL to a frequency comb has been shown, with the latter derived from a traceable ... See full document

... The substrate was reduced to 100 m using mechanical lapping, and diced into a standalone 100 - m -wide chip. Fig. 2 (a) shows the micro-machined waveguide block assembly, including two half-blocks with a diagonal ... See full document

... tially lower peak optical power seen in the measurements (0.8 mW as opposed to 3.5 mW in the simulation) is due in part to the poor collection efficiency (25%) of the detection system used to make the measurement. 18 ... See full document