Mesa‐type quantum cascade lasers fabricated by using inductively coupled plasma reactive ion etching

ABSTRACTGratings in GaAs/AlGaAs mid-infrared quantum cascade lasers (QCLs) are fabricated with a structure depth of more than 10 μm. A N2/SiCl4 inductively coupled plasma reactive ion etching (ICP-RIE) process was employed to achieve extremely smooth sidewalls and selectivities to the SiNX etch mask of up to 70:1. EDX spectra measured on as-etched samples show that sidewall etch inhibition is caused by a thin Si containing layer on the sidewalls that is formed simultaneously with ICP etching of GaAs at the bottom of the trenches. To demonstrate device application gratings with a pitch of 1.72 μm are applied to long rib waveguide -based QCLs emitting at λ = 10.7 μm. When etched laterally together with the rib the grating gives rise to stable single mode emission up to 295K from these QCLs. The respective grating coupling coefficient is determined to be κ = 29 cm-1.

Download Full-text

Terahertz Quantum-Cascade Laser Based on the Resonant-Phonon Depopulation Scheme

International Journal of High Speed Electronics and Systems ◽

10.1142/s012915641640022x ◽

2016 ◽

Vol 25 (03n04) ◽

pp. 1640022 ◽

Cited By ~ 6

Author(s):

Rustam A. Khabibullin ◽

Nikolay V. Shchavruk ◽

Aleksandr Yu. Pavlov ◽

Alexey N. Klochkov ◽

Dmitry S. Ponomarev ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Quantum Cascade Lasers ◽

Ridge Structure ◽

Quantum Cascade ◽

Inductively Coupled ◽

Substrate Removal ◽

Operation Conditions ◽

Metal Waveguide ◽

Band Profile ◽

Cascade Lasers

We have designed GaAs/Al0.15Ga0.85As multilayer heterostructure (MH) with diagonal transitions and optimized oscillator strength – 0.425. We investigate the dependence of the MH energy band profile on the electric field and thermal properties of terahertz quantum cascade lasers (THz QCL) under different operation conditions. Furthermore, we develop a technique for the fabrication of THz QCL with double metal waveguide via low-temperature In-Au wafer bonding followed by substrate removal. Inductively coupled plasma reactive ion etching in BCl3/Ar at 15:15 sccm has been used to obtain ridge structure of various widths with vertical sidewalls.

Download Full-text

Coupled Cavity Mid-IR Quantum Cascade Lasers Fabricated by Dry Etching

Photonics ◽

10.3390/photonics7030045 ◽

2020 ◽

Vol 7 (3) ◽

pp. 45

Author(s):

Kamil Pierściński ◽

Dorota Pierścińska ◽

Aleksandr Kuźmicz ◽

Grzegorz Sobczak ◽

Maciej Bugajski ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Quantum Cascade Lasers ◽

Single Mode ◽

Quantum Cascade ◽

Inductively Coupled ◽

Detection Systems ◽

Mode Suppression ◽

Cascade Lasers ◽

Coupled Cavity ◽

Better Than

In this work, two-section, coupled cavity, mid-IR quantum cascade lasers (QCLs) were characterized in terms of their tuning range and emission stability under operation towards potential application in detection systems. Devices were processed by inductively coupled plasma reactive ion etching (ICP-RIE) from InP-based heterostructure, designed for emission in the 9.x micrometer range. Single mode devices were demonstrated with a better than 20 dB side mode suppression ratio (SMRS). The fabrication method resulted in improved yield, as well as high repeatability of individual devices. Continuous, mode-hop-free tuning of emission wavelength was observed across ~4.5 cm−1 for the range of temperatures of the heat sink from 15 °C to 70 °C. Using the thermal perturbation in the lasing cavity, in conjunction with controlled hopping between coupled-cavity (CC) modes, we were able to accomplish tuning over the range of up to ~20 cm−1.

Download Full-text