Real-time screen-aided multiple-image optical holographic matched-filter correlator

Area of Science:

• Optics
• Information Processing
• Materials Science

Background:

• Multiplex holographic filtering is crucial for advanced optical processing.
• Real-time coherent optical correlators require efficient filtering components.
• Contact screens offer a method for implementing holographic filters.

Purpose of the Study:

• To present the principle and experimental results of using contact screens for multiplex holographic filtering.
• To describe the design and fabrication of 1-D and 2-D gray density screens and 2-D dichromated gelatin phase screens.
• To evaluate the efficiency and performance of these screens in a real-time coherent optical correlator.

Main Methods:

• Fabrication of 1-D and 2-D gray density contact screens.
• Fabrication of 2-D dichromated gelatin phase screens.
• Experimental application of screens in a real-time coherent optical correlator for multiplex holographic filtering.

Main Results:

• 2-D density-type screens produced a 5x5 array of spectrum islands but suffered from low light efficiency.
• Dichromated gelatin phase screens were developed to overcome the efficiency limitations of density-type screens.
• A functional phase screen demonstrated reasonable efficiency for multiplex holographic filtering in the real-time correlator.

Conclusions:

• Dichromated gelatin phase screens are a viable, more efficient alternative to density-type screens for multiplex holographic filtering.
• Despite fabrication challenges, phase screens show promise for enhancing real-time optical correlator performance.
• The study validates the application of contact screens for effective multiplex holographic filtering in optical processors.