Polycrystalline silicon optical fibers with atomically smooth surfaces.

Area of Science:

• Materials Science
• Optical Engineering
• Nanotechnology

Background:

• Polycrystalline silicon (polysilicon) optical fibers offer potential for nonlinear optical applications.
• Fabrication challenges include achieving low-loss transmission and ultrasmooth core surfaces.

Purpose of the Study:

• To investigate the surface roughness of polysilicon core optical fibers.
• To quantify the impact of core-cladding interface scattering on optical losses.
• To assess the suitability of these fibers for nonlinear optics.

Main Methods:

• Fabrication of polysilicon core optical fibers via high-pressure chemical deposition.
• Measurement of optical transmission for fibers with varying core sizes.
• Direct surface roughness measurement using a 3D optical profiler (Zemetrics ZeScope).

Main Results:

• Optical transmission measurements indicated negligible scattering losses from the core-cladding interface.
• Direct surface profiling confirmed an ultrasmooth core surface with roughness of approximately 0.1 nm.
• The results demonstrate the feasibility of fabricating low-loss polysilicon optical fibers.

Conclusions:

• High-pressure chemical deposition enables the fabrication of polysilicon optical fibers with ultrasmooth cores.
• Scattering losses at the core-cladding interface are minimal, allowing for low-loss transmission.
• These low-loss, ultrasmooth polysilicon fibers are scalable to submicrometer dimensions and suitable for nonlinear optical applications.