Diffractive optics development using a modified stack-and-draw technique.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Standard surface relief diffractive optical elements (DOEs) present fabrication challenges and integration difficulties.
• Existing methods for creating phase shifts in DOEs are often complex and limit their application.

Purpose of the Study:

• To introduce a novel method for fabricating diffractive optical elements (DOEs) using refractive index variations.
• To demonstrate a flat, easily integrable DOE for optical fiber applications.
• To showcase the potential of this DOE as a fiber interconnector.

Main Methods:

• A modified stack-and-draw technique, adapted from photonic crystal fiber fabrication, was employed.
• Two types of glass with differing refractive indices (NC21 and F2) were used to create phase shifts.
• A proof-of-concept two-dimensional binary optical phase grating (chessboard pattern, 5 μm pixel size) was fabricated.

Main Results:

• A completely flat diffractive optical element (DOE) was successfully fabricated.
• The fabricated DOE demonstrated effective light coupling from a small-core fiber to a multicore fiber.
• Numerical and experimental results confirmed the DOE's functionality as a fiber interconnector.

Conclusions:

• The novel method offers a simplified approach to DOE fabrication, yielding flat, integrable optical components.
• Refractive index variation using different glasses is a viable technique for creating phase shifts in DOEs.
• The demonstrated DOE serves as an effective solution for fiber interconnectivity in optical systems.