Month: April 2017

The Significance of Fused Couplers in the Optical World

Fused couplers are in use for several years now. They are generally meant for two actions- splitting optical signals between two fibers and to combine optical signals from two fibers into one fiber. Fused couplers are constructed by fusing and tapering two fibers together. This method provides a simple, rugged, and compact method of splitting and combining optical signals.

Fused Optic Couplers can be broadly classified into passive devices. For passive fiber optic couplers, there is no power required for operation. Fiber Optic Couplers can be of various types. For example, 1X N Singlemode couplers, PM Fiber Couplers, starsand trees coupler, etc. Let’s understand them in detail:-

  • 1X N Singlemode couplers: Splitters supply N outputs by using the single optical signal.
  • Tree Couplers: The Tree couplers are capable of executing both the functions, that of combiners as well as splitters, in just one device. This categorization is generally based upon the number of inputs and outputs ports. They are either multi-input with a single output or single input with a multi-output.
  • PM Couplers: PM coupler stands for Polarization Maintaining Fiber Coupler. It is a device that either splits the light rays from the input PM fiber into multiple outputs PM fibers or coalesces the luminosity signals from two PM fibers into a one PM fiber. The applications of PM couplers include signal monitoring in its systems, PM fiber interferometers, and also power sharing in polarization sensitive systems, etc.
  • Star Coupler: Star couplers distribute power from the inputs to the outputs.

Now coming to the benefits of these Fiber Optical Couplers, they are as follows:-

  • Low excess loss
  • High stability
  • High reliability
  • Low polarization dependent loss
  • Dual operating window
  • High directivity and Stumpy insertion loss.

There are several innovative and leading companies in the market that are providing supreme quality fiber optical components. These companies are containing teams of optical component engineers having tons of experience.. They provide cost effective solutions based on Fused Fiber Couplers, PLC, CWDM/DWDM Filters, Pump Combiners, PM Fiber Components, Isolators , and Integrated Modules technologies.

Two Types Of Polarization Beam Combiners & Splitters

Polarizing Beam combiners / splitters are the devices used to combine two polarized light signals or split single non-polarized light into two polarized parts. These combiners and splitters are designed and developed to split light beams by deploying the polarization state and not by wavelength or intensity.

The polarizing beam splitters / combiners typically have 0° or 45° angle of incidence and a 90° division between the beams; this generally depends on the configuration. There are two types of Polarization beam combiners / splitters; these are described below:

  1. Incoherent Polarization Combining / Splitting

The Incoherent combining or splitting is the simpler variant and the basic technique. In this method, the resulted beams of two broad area laser diodes are sent onto a thin-film polarizer so as to reflect one of the beams while transmit the other; both of these beams then propagate in the same direction. As a result, one attains an unpolarized beam (with the combined optical power of the input beams) and the same beam quality. Consequently, the brightness gets nearly doubled.

This technique is often used for any-a-applications, for instance, end-pumping of a solid state laser with an increased power. However, the technique is not suitable for power scaling.

  1. Coherent Polarization Combining / Splitting

With coherent beam combining or splitting it is viable to attain a linear polarized state in the output, if two mutually coherent beams are combined. If two ports have the equal input powers, the output polarization would be typically rotated by 45° -depending on the polarization direction of any of the input beams.

Also, the coherent polarization combining can be repeated several times because of the linear output polarization. Thereby, this technique is suitable for power scaling.

A polarization beam combiner and splitter is often used in photonics instrumentation, optics and semiconductors to transmit p-polarized light while reflecting s-polarized light. These hold a world of worth when it comes to optics, telecommunication and fiber applications, and make the working effective as well as effortless.