Abstract
In this work, we improved the performance of mid-infrared type II InSb/InAs quantum dot (QD) laser diodes by incorporating a lattice-matched p-InAsSbP cladding layer. The resulting devices exhibited emission around 3.1 µm and operated up to 120 K in pulsed mode, which is the highest working temperature for this type of QD laser. The modal gain was estimated to be 2.9 cm−1 per QD layer. A large blue shift (~150 nm) was observed in the spontaneous emission spectrum below threshold due to charging effects. Because of the QD size distribution, only a small fraction of QDs achieve threshold at the same injection level at 4 K. Carrier leakage from the waveguide into the cladding layers was found to be the main reason for the high threshold current at higher temperatures.
Highlights
The mid-infrared wavelength range (2–5 μm) continues to attract significant research interest due to its importance for various potential applications, such as optical gas sensing, environmental pollution monitoring, chemical process control, non-invasive medical diagnosis, tunable IR spectroscopy, laser surgery and infrared countermeasures [1]
Type II InSb/InAs quantum dot (QD) grown by molecular beam epitaxy (MBE), which have exhibited room temperature mid-infrared photo-luminescence (PL) [7] and electro-luminescence (EL) [8], could be a route towards QD light sources and lasers emitting beyond 3 μm
QD laser diodes with different cavity lengths were tested in pulsed mode (100 ns pulse width, 2 kHz repetition rate) from 4 K to 120 K
Summary
The mid-infrared wavelength range (2–5 μm) continues to attract significant research interest due to its importance for various potential applications, such as optical gas sensing, environmental pollution monitoring, chemical process control, non-invasive medical diagnosis, tunable IR spectroscopy, laser surgery and infrared countermeasures [1]. The growth conditions for successful realization of QDs needs careful attention to detail to obtain the correct size distribution and area density, once these conditions are established the active region growth can be completed and does not require an extended growth period Despite these potential merits, to date there are still very few reports on QD lasers in the mid-infrared range and their performance lags behind the aforementioned types of lasers. The laser diodes worked up to 120 K in pulsed mode, which is a significant improvement compared with previous work [9,10] The gain of these type II QDs was estimated and the different contributions to the threshold current were studied
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
