Fabrication Of Fiber Couplers Research Articles

Fabrication of waveguide directional couplers using 2-photon lithography.

Advances in 2-photon lithography have enabled in-lab production of sub-micron resolution and millimeter scale 3D optical components. The potential complex geometries are well suited to rapid prototyping and production of waveguide structures, interconnects, and waveguide directional couplers, furthering future development and miniaturization of waveguide-based imaging technologies. System alignment is inherent to the 2-photon process, obviating the need for manual assembly and allowing precise micron scale waveguide geometries not possible in traditional fused fiber coupler fabrication. Here we present the use of 2-photon lithography for direct printing of multi-mode waveguide couplers with air cladding and single mode waveguide couplers with uncured liquid photoresin cladding. Experimental results show reproducible coupling which can be modified by selected design parameters.

Estimation of coupling parameters for auto‐motorized fabrication of fused fiber coupler

AbstractA directional fiber coupler with exertion loss 0.03 dB has been successfully fabricated using fusion technique with typical coupling ratio 1–90%. The coupling region of two twisted single mode fiber is heated by injecting hydrogen gas at 2.5 bar. During fusion process, both two sides of fibers are pulled by stages that are automatically motorized in range of 800–4800 μm, and stopped when the desired coupling ratio is reached. The parameters of automated mechanical motion of pulling stages and coupling parameters at fusion region have been calculated by using kinetic model. The effect of heating and elongation reduces the diameter of cross section tapered region with a diameter 6.35 micrometer scale. As the fabrication of fiber couplers described by degree of fusion, which is function of heating and pulling length, it can be seen clearly that the coupling coefficient between the fibers increases exponentially with increasing the degree of fusion. However, by knowing coupling power and mechanical motion parameters, the fabrication of directional fiber coupler can be optimized. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1932–1935, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26937

Specialty Fiber Coupler: Fabrications and Applications

We review the research on specialty fiber couplers with emphasis placed on the characteristics that make them attractive for biomedical imaging, optical communications, and sensing applications. The fabrication of fiber couplers has been carried out with, in addition to conventional single mode fiber, various specialty fibers such as photonic crystal fiber, double clad fiber, and hole-assisted fiber with a Ge-doped core. For the fiber coupler fabrication, the side polishing and the fused biconical tapered methods have been developed. These specialty fiber couplers have been applied to optical coherence tomography, fluorescence spectroscopy, fiber sensors, and optical communication systems. This review aims to provide a detailed statement on the recent progress and novel applications of specialty fiber couplers.

Characteristics of Ceramic Microheater for Fiber Coupler Fabrication

Properties of a microheater have been greatly improved for use in fused-tapered fiber coupler fabrication by employing a ceramic heat source. Lanthanum chromite was adopted as a heat source because it has the highest melting point for the use in air and can be used without cooling equipment. The usual susceptibility to heat shock exhibited by ceramic heaters was essentially overcome by miniaturizing the structure so that it could handle quick temperature changes during fiber coupler fabrication. The microheater was typically only 22 mm long which helps shorten the fiber coupler length. The lifetime of the microheater was about 1500 h at 1530°C. This is more than 100 times that of the previously developed precious metal microheater. There was only a slight change in the temperature distribution along the heater with heating time. 1.31/1.55-µm wavelength-division-multiplexing (WDM) couplers were fabricated during the lifetime test and it was confirmed that the coupling properties could be very well controlled even after the test.

Reproducible fabrication method for polarization preserving single-mode fiber couplers

The adaptation of the biconically-tapered-fused (BTF) fiber coupler fabrication approach to polarization preserving fiber couplers is reported. Two practical methods for identifying and aligning the birefringent axes of the fibers forming the coupler are described. The fabrication approaches are highly reproducible and the 3-dB couplers fabricated exhibit less than 1.0-dB insertion loss, controllable splitting ratio, and an average polarization extinction ratio of 15 to 20 dB. >