Spectral phase noise analysis of a cryogenically cooled Ti:Sapphire amplifier

Area of Science:

• Laser Physics
• Optical Engineering
• Cryogenics

Background:

• Ti:Sapphire amplifiers are crucial for ultrafast science.
• Understanding spectral phase noise is vital for precision applications.
• Cryogenic cooling can impact laser performance and stability.

Purpose of the Study:

• To precisely analyze the spectral phase noise of a cryogenically cooled Ti:Sapphire amplifier.
• To quantify the noise contributions from the cooling system (vacuum pumps and cryogenics).
• To investigate the thermal and mechanical origins of carrier-envelope phase noise at various repetition rates.

Main Methods:

• Spectrally resolved interferometry was employed for high-precision relative phase difference measurements.
• Carrier-envelope phase noise was analyzed for different laser repetition rates.
• Mechanical vibrations were measured using an accelerometer and compared with interferometric data.

Main Results:

• The cooling system's contribution to spectral phase noise was found to be below 50 mrad.
• Thermal and mechanical noise sources affecting carrier-envelope phase were identified.
• Correlations between mechanical vibrations and phase noise were investigated.

Conclusions:

• Cryogenic cooling of Ti:Sapphire amplifiers introduces minimal spectral phase noise.
• The study successfully differentiated and quantified thermal and mechanical noise contributions.
• Spectrally resolved interferometry provides a powerful tool for characterizing laser phase noise.