Indirect spectrum measurement via random phase modulation and detection in temporal domain

Area of Science:

• Optics and Photonics
• Spectroscopy
• Physical Phenomena

Background:

• Spectroscopy is crucial for understanding fundamental physical phenomena.
• Traditional dispersive Fourier transformation (DFT) for spectral measurement is limited by far-field detection requirements.
• These limitations necessitate exploring alternative, more adaptable measurement strategies.

Purpose of the Study:

• To develop an indirect spectrum measurement method overcoming traditional limitations.
• To enable spectrum reconstruction via near-field detection.
• To investigate the impact of near-field operations on spectroscopy parameters.

Main Methods:

• Inspired by Fourier ghost imaging principles.
• Utilized random phase modulation for indirect spectrum measurement.
• Employed time-domain near-field detection.

Main Results:

• Successfully reconstructed spectrum information through near-field detection.
• Significantly reduced the required length of dispersion fiber.
• Substantially decreased optical loss compared to far-field methods.

Conclusions:

• The proposed indirect spectrum measurement effectively overcomes traditional limitations.
• Near-field operations offer advantages in reduced fiber length and optical loss for spectroscopy.
• Further investigation into spectrum resolution, measurement range, and photodetector bandwidth is warranted for practical applications.