Experimentally generating any desired partially coherent Schell-model source using phase-only control

Abstract

A technique is presented to produce any desired partially coherent Schell-model source using a single phase-only liquid-crystal spatial light modulator (SLM). Existing methods use SLMs in combination with amplitude filters to manipulate the phase and amplitude of an initially coherent source. The technique presented here controls both the phase and amplitude using a single SLM, thereby making the amplitude filters unnecessary. This simplifies the optical setup and significantly increases the utility and flexibility of the resulting system. The analytical development of the technique is presented and discussed. To validate the proposed approach, experimental results of three partially coherent Schell-model sources are presented and analyzed. A brief discussion of possible applications is provided in closing.

Generating partially coherent Schell-model sources using a modified phase screen approach

“…4. In contrast to the CS approach, the MPS method does not yield a fully developed speckle pattern in the source plane.…”

“…Expanding γ in a Maclaurin series and keeping the first two terms yields Schell-model sources with power-exponential-type coherence functions. 4 Although Eq. (5) cannot be satisfied in general, χ ≈ μ if ϕ ¼ argðTÞ.…”

“…4 Here, an improvement to the CS approach presented in Ref. 4 is introduced. Similar to the concept presented in Ref.…”

“…4 The method uses a single phase-only SLM to produce complex phase screens [complex screens (CS), hereafter], i.e., screens that impart changes to both the amplitude and phase of an initially coherent light source. Using this approach, any desired Schell-model source can be produced.…”

Generation of partially coherent beams with controllable time-dependent coherence

“…Although using an SLM can quantitatively control the coherence of the light, the coherence of the light remains invariant in most of the studies. 14,[16][17][18][19][20][21] Furthermore, some studies are limited to the theoretical simulations 14,18 or focused only on the intensity distribution. 16,19,20 To the best of our knowledge, the generation of partially coherent beam with temporally variable coherence by using an SLM has not been reported.…”