PM Couplers

PM Couplers


  • Optical amplifiers
  • Fiber lasers
  • Power monitoring
  • Fiber gyroscopes
  • Coherent communications
  • Key Features

  • Low loss and cost
  • Broad bandwidth
  • Good uniformity
  • Small package
  • High directivity
  • Wide variety of wavelengths 780 nm–2005 nm
  • Fused couplers are used to split optical signals between two (or more) fibers or to combine optical signals from two (or more) fibers into one fiber. They are constructed by fusing and tapering the fibers together. This method creates a simple, rugged, compact method of splitting or combining optical signals. Typical excess losses are as low as 0.2 dB, while split ratio tolerances range from ±5% to ±0.5% at design wavelengths depending upon the splitting ratio. These devices are bidirectional and offer low backreflection and insertion losses.

    Fused PM Splitters exhibit a broad operating wavelength range of up to ±20 nm for 1550 nm region devices. For operation within the standard bandwidth of a splitter, it is best to order a standard center wavelength for lowest price and quickest delivery. Fused PM splitters are also available on smaller core fibers for 1064 nm, 980 nm and other wavelengths. (Nonstandard center wavelengths may require minimum order quantities or set up charges.

    A wide variety of options are available for fused PM splitters. Standard configurations are 1x2, 2x2, 1x3 (monolithic) and 1x4 (compact cascaded). A monolithic structure means that all fibers are fused together, while a cascaded device combines several 2x2 splitters to create a greater split count.

    Connectorize the fibers of fused splitters with all standard connectors such as FC, SC, ST, LC etc. and finishes (Super PC, Ultra PC, Angled PC [APC] etc.).

    Some customers request a high split ratio (90/10, 95/5) in order to tap off a small amount of light for power monitoring. Our offers a revolutionary technology where we can tap a small percentage (1% to 3% typically) of the light in the fiber and directly couple it into a photodiode. This method has minimal loss, high extinction ratio and is very inexpensive (see the Optical Power Monitors / Taps data sheet). Fused splitters have an extinction ratio specification of 17-20 dB for the main through port. Our inline miniature splitters (FOBS-12N) offer 20 dB, and the larger

    Parameter Condition Value
    Split Ratio 2 ddd 50/50, 90/10, 95/5 %
    Split Ratio Tolerance 95/5 ±1.5 %
    90/10 ±2.2 %
    50/50 ±5 %
    Center wavelength 780, 850, 1064, 1310, 1480, 1550, 2005 nm2
    Bandwidth ±1.25 % of center wavelength, ±20 nm3
    td>>Polarization Extinction Ratio Through port 23 dB typical, 20 dB minimum 4
    Tap port 17 dB typical, 15 dB minimum 4
    Return Loss < 50 dB
    Directivity <55 dB
    Excess Loss Typical 0.2 dB 5
    Maximum <0.4 dB 5
    Operating Temperature 0°C to 70°C
    Storage Temperature -40°C to 85°C

    1 For 780, 850, 1064, 1310, 1480, 1550, 2005 nm devices

    3 Bandwidth may differ for custom wavelengths.

    4 Not including connectors.

    5 Not including connector losses.