Phase-locked high-peak-power sub-ns laser for electron modulation in quasi-steady-state microbunching

Area of Science:

• Physics
• Laser Technology
• Accelerator Science

Background:

• Steady-state microbunching (SSMB) is a promising concept for generating high-average-power, short-wavelength coherent radiation.
• Experimental validation of quasi-SSMB requires precise, turn-by-turn coherent modulation of electron bunches in storage rings.

Purpose of the Study:

• To develop and demonstrate a dedicated phase-locked pulse laser system for coherent modulation of electron bunches.
• To achieve high peak power and high repetition rate for laser pulses essential for SSMB experiments.

Main Methods:

• A master oscillator power amplifier (MOPA) architecture combined with continuous-wave (CW) seed laser electro-optic gating was employed.
• An optical phase-locked loop (OPLL) utilized an iodine frequency-stabilized CW seed laser for phase locking.
• Laser pulses were characterized for pulse width, repetition rate, and peak power.

Main Results:

• The developed laser system produced 1064 nm laser pulses with a 0.5 ns pulse width, 6.25 MHz repetition rate, and 32 kW peak power.
• Significant phase noise suppression was achieved in the 10 Hz-10 kHz range, confirmed by beat signal measurements.
• The system successfully demonstrated phase-locked laser pulse generation at high repetition rates.

Conclusions:

• A method for laser-based coherent modulation on electron bunch trains was successfully proposed and demonstrated.
• The developed laser system provides a versatile design for generating phase-locked laser pulses suitable for SSMB research.
• This work is critical for advancing the experimental validation of SSMB light sources.