Power stabilization of a diode laser with an acousto-optic modulator

Area of Science:

• Optics and Photonics
• Laser Physics
• Experimental Physics

Background:

• Laser power fluctuations degrade device performance, affecting signal-to-noise ratio, accuracy, and repeatability.
• Both high-frequency noise and slow power variations pose challenges in laser applications.

Purpose of the Study:

• To experimentally investigate and demonstrate power stabilization for a diode laser system.
• To quantify the effectiveness of an acousto-optic modulator in reducing laser power noise.

Main Methods:

• Utilized an acousto-optic modulator for active feedback control of diode laser power.
• Performed frequency-domain analysis to measure relative power noise.
• Conducted time-domain analysis using Allan standard deviation to assess long-term stability.

Main Results:

• Achieved relative power noise reduction to 2.2 × 10^-8 Hz^-1/2 in the 1-100 kHz range.
• Measured a relative Allan standard deviation of 6 × 10^-7 at 100 s averaging time.
• Observed increased instability beyond 100 s, reaching 2 × 10^-6 at 10 000 s.

Conclusions:

• The acousto-optic modulator effectively stabilizes diode laser power across different timescales.
• The stabilization technique significantly improves signal-to-noise ratio and device repeatability.
• This method offers a viable solution for enhancing laser performance in sensitive applications.