High Density Fiber Optic Array Precision Polishing

by www.fiber-mart.com

High density fiber optic array polishing to tightest optical specifications with fiber-end surface finish to a few manometers Ra, is now offered as a service to fiber optic array manufacturers.

 

For applications including: Fiber optics, fiber optic arrays, waveguides, optical switches, WSXC (Wavelength Selective Cross-connects), matrix optical switches, transparent optical cross-connect switches, precision polished NxN switches, MEMS (Micro Electromechanical Systems) devices. As a stand-alone device, fused arrays offer very high coupling efficiency, high chemical resistance and high damage threshold. Coupled to one or more other fibers, the fused arrays become highly efficient fiber beamsplitters and fiber beam combiners.

 

Ensuring top performance of fiber optic high density arrays, presents many challenges to manufacturers of these devices, particularly in the assembly and polishing operations. Tens, hundreds or even thousands of optical fibers must be assembled with positioning tolerances within several microns. These fibers, each consisting of a 5 to 10 micron core with cladding and coating surrounding it, must then be molded together, terminating into a planar surface. The ends of these fibers must then be polished to near perfection, with flatness within a few microns from edge to edge, and very high quality optical surface finishes to < 5 angstroms. Surface finish and flatness are critical in order to maintain signal integrity and minimize loss. Traditional optical polishing techniques cannot achieve these high-performance specifications.

 

After extensive R&D efforts, Valley Design has developed the process and equipment fixturing required to provide these services. Valley has closely collaborated with several customers to provide prototype to production high quality polishing of fiber optic arrays.

 

Application For Optical Switch Polishing

Matrix optical switches, also called NxN switches, allow any input channel to be switched to any output channel. The primary objective is to enable transparent optical cross-connects where the applied signal will remain in the optical mode, and not require optical to electronic to optical conversions. For example, 64 light beams from an 8×8 fiber optic array are intercepted by an 8×8 MEMS-based array of 64 mirrors that move in and out of the beam path. MEMS are tiny mechanical components fabricated by photolithographic technology, typically on a Silicon substrate. These are movable, and in this case, the movable components are mirrors. These fiber optic arrays need to be planarized with a desired flatness of less than 1 micron. The optical fibers themselves also tolerate no imperfections and require a surface finish of only a few nanometers. With over 25 years of polishing experience, Valley can achieve these flatness and surface finish requirements.

 

These are measured and documented by Valley using our in-house optical interferometers and WYKO instrumentation.

 

Valley also provides and processes numerous types of substrate materials used for these applications including Fused Silica, Quartz, Pyrex, Glass, GaAs, LiN, InP, Sapphire, Silicon, Ceramics and many others. Valley can lap, polish, dice and edge or angle polish these parts to your specifications. Coating and metallization services are also provided.