Microgratings for high-efficiency guided-beam deflection fabricated by electron-beam direct-writing techniques

Area of Science:

• Optoelectronics
• Materials Science
• Nanofabrication

Background:

• Integrated optical circuits require efficient microcomponents for beam manipulation.
• Arsenic trisulfide (As(2)S(3)) films are suitable for optical waveguides due to their transparency and processability.
• Microgratings are essential for controlling light propagation in photonic devices.

Purpose of the Study:

• To develop an electron-beam writing apparatus for fabricating microgratings in integrated optical circuits.
• To design and experimentally validate microgratings for high-efficiency guided-beam deflection.
• To investigate both uniform-period and chirped gratings for optical applications.

Main Methods:

• Utilized an electron-beam writing apparatus with computer-processed scanning.
• Fabricated microgratings in As(2)S(3) film waveguides.
• Established design procedures for uniform-period and linearly chirped gratings.

Main Results:

• Achieved high diffraction efficiency (approximately 100%) for uniform-period gratings (0.2 x 1 mm(2)).
• Demonstrated wideband selectivity with high diffraction efficiency for chirped gratings.
• Validated the design and experimental performance of microdeflection gratings.

Conclusions:

• The developed electron-beam system effectively fabricates high-performance microgratings.
• Microgratings are crucial for efficient guided-beam deflection in As(2)S(3) optical waveguides.
• Both uniform-period and chirped gratings offer distinct advantages for integrated optics.