Frequency-dependent linewidth enhancement factor of optical injection-locked quantum dot/dash lasers

Area of Science:

• Optoelectronics
• Semiconductor Lasers
• Quantum Dot Devices

Background:

• Quantum dash/dot semiconductor lasers exhibit unique phase-amplitude coupling characteristics.
• The linewidth enhancement factor (α(H)-factor) and FM-to-AM indices ratio (FAIR) are critical parameters in laser dynamics.
• Understanding these parameters is crucial for laser modulation and performance optimization.

Purpose of the Study:

• To investigate the effect of optical injection on the α(H)-factor and FAIR in quantum dash/dot semiconductor lasers.
• To compare the behavior of these parameters under optical injection versus solitary operation.
• To analyze the influence of modulation frequency on optical injection's effect.

Main Methods:

• Combined theoretical modeling and experimental studies.
• Analysis of α(H)-factor and FAIR under varying optical injection conditions.
• Investigation across a range of modulation frequencies.

Main Results:

• Optical injection strongly modifies the α(H)-factor and FAIR in quantum dash/dot lasers.
• Both α(H)-factor and FAIR are reduced by optical injection at low modulation frequencies.
• Phase-amplitude coupling characteristics show minimal influence from optical injection at high modulation frequencies.

Conclusions:

• Optical injection offers a method to control phase-amplitude coupling in quantum dash/dot lasers.
• The effectiveness of optical injection in modifying α(H)-factor and FAIR is frequency-dependent.
• These findings provide insights for designing and controlling semiconductor laser modulation.