Passively mode-locked glass waveguide laser with 14-fs timing jitter

Area of Science:

• Optics and Photonics
• Laser Physics
• Precision Timing

Background:

• Mode-locked lasers are crucial for generating high-repetition-rate optical pulses.
• Achieving ultralow timing jitter is essential for advanced applications in communications, metrology, and scientific research.
• Traditional methods often face limitations in noise reduction and stability.

Purpose of the Study:

• To develop a method for generating ultralow jitter pulse trains from a passively mode-locked laser.
• To investigate the effectiveness of high-bandwidth feedback control on laser cavity length and pump power for jitter reduction.
• To synchronize a high-frequency laser to an external clock signal with unprecedented timing precision.

Main Methods:

• Utilized a passively mode-locked, erbium/ytterbium co-doped planar waveguide laser.
• Implemented high-bandwidth feedback control targeting the physical cavity length and optical pump power.
• Synchronized a 750-MHz fundamentally mode-locked laser to an external reference clock.

Main Results:

• Successfully generated ultralow jitter pulse trains.
• Achieved a root-mean-square (RMS) relative timing jitter of 14.4 femtoseconds (fs).
• The jitter was integrated over a wide frequency range from 10 Hz to 375 MHz (Nyquist frequency).

Conclusions:

• High-bandwidth feedback control on cavity length and pump power is an effective strategy for minimizing timing jitter in mode-locked lasers.
• The demonstrated synchronization technique enables highly precise timing control, crucial for demanding applications.
• This work advances the state-of-the-art in stable, high-repetition-rate pulse generation for scientific and technological advancements.