Dual chirped optical pulses from a phase-modulated laser

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Phase-modulated lasers are crucial for generating complex optical signals.
• Spectral carving of laser sidebands enables precise control over optical pulse characteristics.

Purpose of the Study:

• To report the generation of dual chirped optical pulses using a phase-modulated laser.
• To investigate the analytical expressions for pulse duration and chirp parameter.
• To experimentally validate the generated optical pulse trains.

Main Methods:

• Utilizing a phase-modulated laser to generate sidebands around the carrier frequency.
• Employing spectral carving by filtering these sidebands with a Gaussian optical band-pass filter (OBF).
• Analyzing the pulse duration and linear frequency chirp parameter using closed-form expressions.

Main Results:

• Successfully generated optical pulse trains with a 5 GHz repetition rate and 29.4 ps pulse duration.
• Experimental results showed good agreement with analytical predictions (28.2 ps) and numerical simulations (27.7 ps).
• Demonstrated the ability to control pulse duration and chirp through modulation index and frequency.

Conclusions:

• The spectral carving of phase-modulated laser sidebands is an effective method for producing dual chirped optical pulses.
• The derived closed-form expressions accurately predict the pulse characteristics.
• This technique offers a viable route for generating precisely controlled optical pulse trains for various applications.