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Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Low threshold current and widely tunable external cavity lasers with chirped multilayer InAs/InGaAs/GaAs quantum-dot
Gray Lin1, Pei-Yin Su, Hsu-Chieh Cheng
1Department of Electronic Engineering and Institute of Electronics, National Chiao-Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan. graylin@mail.nctu.edu.tw
Optics Express
|March 16, 2012
Summary
This study demonstrates widely tunable indium arsenide/gallium arsenide (InAs/GaAs) quantum-dot lasers with low threshold current density. Shorter cavity designs achieve extended tuning ranges and record low injection currents.
Area of Science:
- Semiconductor Lasers
- Quantum Dot Physics
- Optoelectronics
Background:
- Indium arsenide/gallium arsenide (InAs/GaAs) quantum dots are promising for laser applications due to their unique electronic and optical properties.
- Achieving wide tunability and low threshold current density in quantum-dot lasers remains a key challenge for practical applications.
Purpose of the Study:
- To implement and characterize grating-coupled external-cavity InAs/GaAs quantum-dot lasers.
- To investigate the impact of cavity length on laser performance, focusing on threshold current and tuning range.
- To propose strategies for the design and optimization of multilayer quantum-dot structures for enhanced laser performance.
Main Methods:
- Fabrication of InAs/GaAs quantum-dot lasers with a grating-coupled external-cavity arrangement.
- Measurement of threshold current density and optical output across a wide tuning range.
- Systematic variation of cavity length to analyze its effect on tuning characteristics.
Main Results:
- A tuning range of 130 nm (1160–1290 nm) was achieved with threshold current density below 0.9 kA/cm² and no observed threshold jump.
- A shorter-cavity device demonstrated a further extended tuning range of 150 nm (1143–1293 nm) with a record low injection current of 90 mA.
- The study provides insights into the relationship between cavity length and tuning performance.
Conclusions:
- Grating-coupled external-cavity configurations enable low-threshold, widely tunable InAs/GaAs quantum-dot lasers.
- Cavity length is a critical parameter for optimizing tuning range and injection current.
- The findings support the development of advanced quantum-dot laser designs for various optoelectronic applications.
