Planarized THz quantum cascade lasers for broadband coherent photonics
arXiv:2207.06737 · doi:10.1038/s41377-022-01058-2
Abstract
Recently, there has been a growing interest in integrated THz photonics for various applications in communications, spectroscopy and sensing. We present a new integrated photonic platform based on active and passive elements integrated in a double-metal, high confinement waveguide layout planarized with a low-loss polymer. An extended top metallization results in low waveguide losses and improved dispersion, thermal and RF properties, as it enables to decouple the design of THz and microwave cavities. Free-running on-chip quantum cascade laser combs spanning 800 GHz, harmonic states over 1.1 THz and RF-injected broadband incoherent states spanning over nearly 1.6 THz are observed. With a strong external RF drive, actively mode-locked pulses as short as 4.4 ps can be produced, as measured by SWIFTS. We demonstrate as well passive waveguides with low insertion loss, enabling the tuning of the laser cavity boundary conditions and the co-integration of active and passive components on the same THz photonic chip.
27 pages, 5 figures
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Cited by in corpus (6)
- Frequency-modulated combs via on-chip field enhancement
- THz optical beat-note detection with a fast Hot Electron Bolometer operating up to 31 GHz
- Broadband surface-emitting THz laser frequency combs with inverse-designed integrated reflectors
- RF Injection Locking of THz Metasurface Quantum-Cascade VECSEL
- Continuously tunable coherent pulse generation in semiconductor lasers
- Spectral shaping of fast-gain frequency combs through phases in synthetic dimensions