Efficient phase-sensitive compensation in lossy interferometry using optical amplification

Area of Science:

• Quantum Optics
• Precision Measurement

Background:

• Optical interferometers are crucial for precision measurements but suffer from sensitivity reduction due to optical path losses.
• These losses introduce vacuum noise, degrading phase estimation accuracy.

Purpose of the Study:

• To propose and validate an enhanced interferometer scheme using a Raman amplifier to mitigate sensitivity loss.
• To investigate the impact of amplifier positioning (pre-amplification vs. post-amplification) on sensitivity.

Main Methods:

• Integration of a Raman amplifier within the lossy interference arm of an optical interferometer.
• Comparative analysis of pre-amplification (PRA) and post-amplification (POA) strategies.
• Experimental validation of the proposed scheme under varying loss conditions.

Main Results:

• Pre-amplification (PRA) significantly outperforms post-amplification (POA) in enhancing phase sensitivity.
• PRA effectively increases phase-sensitive particles and minimizes noise amplification, especially at high loss levels.
• Experimental demonstration showed a 4.6 dB sensitivity improvement at 90% loss with PRA, equivalent to an 8x increase in laser power.

Conclusions:

• The proposed PRA-enhanced interferometry scheme offers a simple yet effective method to improve robustness against significant optical losses.
• This technique facilitates practical phase measurement in lossy environments, enhancing the applicability of optical interferometers.