A5071997185- Spectroscopy and Laser Applications
- Advanced Fiber Laser Technologies
- Terahertz technology and applications
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Atmospheric Ozone and Climate
ETH Zurich
2023-2024
THz quantum cascade lasers (QCLs) based on double metal waveguides feature broadband and high-temperature devices for their use in spectroscopy sensing. However, extreme field confinement produces poor output coupling efficiencies divergent far-fields. Here, we present a planarized QCL with an inverse-designed end facet reflector coupled to surface-emitting patch array antenna. All the components have been optimized octave-spanning spectral bandwidths between 2 4 monolithically integrated...
We will present new developments in THz coherent photonics enabled by a recently demonstrated broadband planarized platform based on quantum cascade gain medium. The possibility to integrate onto the same chip active (lasers, detectors, amplifiers) and passive (waveguides, splitters, antennas, chirped mirrors,) photonic elements results extremely attractive, naturally bridging microwaves waves. Such approach allows adoption of advanced design techniques (inverse design) tailor facet...
We present a high-performance planarized waveguide THz quantum cascade laser frequency comb, where an inverse-designed active front facet with reduced reflectivity is coupled to patch array antenna, and all the components are optimized for octave-spanning emission spectrum (2-4 THz). Broadband comb states spanning over 800 GHz single narrow RF beatnote up -50 dBm measured at 20 K. The slope efficiency improved by around five times, peak output power of 13 mW in pulsed mode (10% duty cycle...
THz quantum cascade lasers (QCLs) based on double metal waveguides feature broadband and high-temperature devices for use in spectroscopy sensing. However, their extreme field confinement produces poor output coupling efficiencies divergent far-fields. Here, we present a planarized QCL with an inverse-designed end facet reflector coupled to surface-emitting patch array antenna. All the components have been optimized octave-spanning spectral bandwidths between 2-4 monolithically integrated...
Terahertz (THz) quantum cascade lasers (QCLs) are compact sources of coherent THz radiation which can also operate as frequency combs [1], making them appealing for spectroscopy and sensing. We recently developed a new planarized QCL platform, where the active region waveguides surrounded by low-loss polymer (BCB). This enables fabricating an extended top metallization placing bonding wires over passive area on sides (see Fig. 1a). have shown that waveguide geometry improves thermal, RF...
THz Quantum Cascade Lasers are unipolar electrically driven semiconductor lasers that can also operate as frequency combs for broadband metrology and sensing [1], [2]. quantum cascade usually processed in double metal waveguide ridges exhibiting low slope efficiencies a patterned far field [3]. Surrounding the ridge structure with low-loss polymer Benzocyclobuten (BCB) allows an extended top contact improving thermal properties well permitting implementation of passive structures [4].
We present a planarized waveguide cavity with an integrated broadband output coupler that improves both the power and far-field properties of THz quantum cascade laser frequency combs. The mirror reflectivity can be tuned by shape end facet, which is obtained efficient inverse design algorithm, where structure iteratively updated to match desired figure merit. Surface emission achieved patch-array antenna, all components have been optimized for octave-spanning spectra (2-4 THz)....
We present a broadband, monolithic outcoupler based on planarized double metal waveguides that addresses both the reflectivity design and broadband narrow beam emission in THz quantum cascade lasers. The waveguide mirror can be adjusted by shaping end facet, obtained with an efficient inverse algorithm. laser radiation is coupled to patch-array antenna for surface emission. All components are optimized octave-spanning spectra between 24 THz. implement these concepts demonstrate...
We present a broadband planarized THz quantum cascade laser with inverse-designed waveguide facets, coupled to patch array antenna for surface emission. measure an emission spectrum spanning 800 GHz, peak power of 13.5 mW and symmetric far-field pattern narrow beam divergence <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(21^{\circ}\ \mathrm{x}\ 20^{\circ})$</tex> .