Passive coupled-cavity mode-locked color-center lasers

Area of Science:

• Laser physics
• Quantum optics
• Solid-state spectroscopy

Background:

• Color-center lasers are tunable solid-state lasers.
• Mode-locking is a technique to generate ultrashort laser pulses.
• Coupled-cavity lasers offer enhanced control over pulse characteristics.

Purpose of the Study:

• To achieve stable, self-starting operation of coupled-cavity mode-locked color-center lasers.
• To generate subpicosecond pulses using nonlinear optical phenomena.
• To explore the use of semiconductor diode optical amplifiers in laser cavities.

Main Methods:

• Incorporation of a semiconductor diode optical amplifier into the control cavity of a KCl:T1(0)(1) color-center laser.
• Adjustment of the amplifier drive current to control nonlinearity.
• Exploitation of saturable gain and saturable absorption regimes.
• Demonstration of self-starting operation.

Main Results:

• Stable, self-starting operation was achieved for a coupled-cavity mode-locked KCl:T1(0)(1) color-center laser.
• Subpicosecond pulses were generated by exploiting saturable gain or saturable absorption.
• Pulse durations as short as 280 femtoseconds (fs) were obtained under saturable gain.
• Self-starting was also demonstrated for a coupled-cavity mode-locked NaCl:OH(-) color-center laser.

Conclusions:

• Semiconductor diode optical amplifiers are effective for achieving stable, self-starting mode-locking in color-center lasers.
• The technique allows for precise control over pulse duration through nonlinear regimes.
• This method broadens the applicability of color-center lasers for generating ultrashort pulses.