Theory of bistability in two-segment diode lasers

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Laser Physics

Background:

• Optical bistability is a key phenomenon in nonlinear optics.
• Two-segment diode lasers offer tunable optical properties.
• Inhomogeneous injection complicates laser dynamics.

Purpose of the Study:

• To investigate optical bistability in two-segment diode lasers with inhomogeneous injection.
• To derive a simple condition for achieving bistability.
• To analyze the impact of carrier recombination rates on bistability.

Main Methods:

• Analytical solution of the rate-equation model.
• Modeling of carrier dynamics in gain and absorber regions.
• Investigation of device parameters like carrier lifetimes and optical cross sections.

Main Results:

• A simple condition for optical bistability was derived.
• Slower carrier recombination in the absorber is necessary for bistability when optical cross sections are equal.
• Carrier lifetimes, switch-on/off powers, and currents were analyzed.

Conclusions:

• The study provides a clear condition for achieving optical bistability in inhomogeneous two-segment diode lasers.
• Understanding carrier recombination dynamics is crucial for designing bistable laser devices.
• The findings contribute to the development of advanced semiconductor laser applications.