Interferometric delay tracking for low-noise Mach-Zehnder-type scanning measurements

Area of Science:

• Optics and Photonics
• Ultrafast Science
• Metrology

Background:

• Precise control of optical delay is critical for pump-probe spectroscopy.
• Mechanical scanning in interferometers presents challenges for high-resolution delay determination.

Purpose of the Study:

• To develop and demonstrate a high-precision delay tracking technique for mechanical scanning optical measurements.
• To achieve sub-attosecond precision in relative delay determination.

Main Methods:

• Utilizing a Mach-Zehnder interferometer with a 1.55-µm continuous-wave laser.
• Implementing sinusoidal phase modulation (30 MHz) and signal demodulation at fundamental and second harmonic frequencies.
• Employing high sampling rates (up to 10 MHz) for delay tracking.

Main Results:

• Demonstrated root-mean-square error below 10 attoseconds for relative delay tracking over 1 m arm length.
• Achieved delay determination precision better than 1 attosecond through scan averaging.
• Validated performance with a mechanical chopper for combined lock-in detection and attosecond-precision delay.

Conclusions:

• The developed technique offers unprecedented precision for optical delay control in mechanical scanning setups.
• This advancement enables integration of high-sensitivity detection with sub-attosecond relative delay measurements.
• The method is applicable to various ultrafast optical measurement techniques requiring precise temporal resolution.