Digital phase conjugate mirror by parallel arrangement of two phase-only spatial light modulators

Area of Science:

• Optics and Photonics
• Digital Holography

Background:

• Conventional digital phase conjugation reverses only the phase of light.
• This limitation reduces phase conjugation fidelity, especially for non-uniformly scattered wavefronts.
• Existing methods restrict applications to specific scenarios.

Purpose of the Study:

• To develop a digital phase conjugate mirror capable of time-reversing both amplitude and phase of input light.
• To enhance phase conjugation fidelity and expand its applicability.
• To overcome the limitations of conventional digital phase conjugation systems.

Main Methods:

• Implementation of a digital phase conjugate mirror using parallel-aligned, phase-only spatial light modulators (SLMs).
• Utilizing two phase-only SLMs to achieve simultaneous time-reversal of both amplitude and phase.
• Experimental validation of the system's performance.

Main Results:

• The novel digital phase conjugate mirror successfully time-reverses both amplitude and phase.
• Experimental results demonstrated a significant reduction in background noise.
• Background noise was reduced by 65% when using the system with a holographic diffuser (0.5-degree diffusion angle).

Conclusions:

• The proposed digital phase conjugate mirror effectively addresses the limitations of conventional systems.
• Simultaneous time-reversal of amplitude and phase leads to improved phase conjugation fidelity.
• This technology offers potential for broader applications in optical systems requiring high-fidelity phase conjugation.