Phase-Only CGH Workflow

This page explains the current phase-only workflow at a conceptual level.

What the Workflow Tries to Solve

Phase-only holography usually starts with a desired intensity pattern at one or more observation planes. The system then searches for a phase pattern at the SLM plane whose propagated field produces that target as closely as possible.

Current Building Blocks

Today, the repository exposes the following pieces for this workflow:

• IntensityTarget for specifying the reconstruction objective
• GerchbergSaxtonPhaseOptimizer for a compact iterative phase-only solver
• DoublePhaseAmplitudeCoder for DPAC-based phase-only encoding
• PhaseOnlyLCOSSLM for optional LCOS/SLM-aware phase realization
• HologramPipeline for end-to-end source → SLM → propagation → evaluation

Conceptual Loop

The current Gerchberg-Saxton path can be read as:

1. start from an initial phase
2. propagate to the target plane
3. replace the amplitude with the target amplitude
4. backpropagate to the source plane
5. keep the phase and repeat

This is not yet the entire story of modern inverse design, but it is a solid and understandable baseline. In the current repository, that baseline now sits alongside DPAC and higher-level device-aware phase encoding rather than standing alone as the only phase-only path.

Why This Matters

This workflow is one of the core reasons pado_hologram exists. It is where the repository starts moving beyond a pure optics library and toward a reusable CGH framework.