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How to choose an optical detector for optical power meter?

2020/12/28      view:

Which detector do I need?

It is very important to correctly match the power meter detector type to the application

The correct detector for loss and power measurements on fiber systems will generally be as follows:

InGaAs (Indium Gallium Arsenide)

  • General & precision measurements over 1000 - 1650 nm (other InGaAs detectors) up to the maximum meter range.
  • CWDM or DWDM bands up to the maximum meter range.
  • Single mode-only testing, with high accuracy.

Ge (Germanium)

  • Modest accuracy from 850 - 1550 nm, up to the maximum meter range.
  • Broad single mode & multimode testing.

Don't choose a Ge (Germanium) detector for:

  • Work on WDM systems above 1550 nm. Calibration constants vary by about 2 dB between 1550 -1625 nm, with high temperature sensitivity. Supporting graphs provided below. 
  • 1550 nm testing is also affected in cold temperatures.
  • Precision or laboratory grade accuracy. Ge is inherently non-linear by about 0.04 dB. It has temperature sensitivity, and responsivity is variable across the detector surface.

Si (Silicon)

  • Precision measurement at 600 - 1000 nm up to the maximum meter range.
  • POF, HCS and 850nm-only testing. It won't work for eg 1300 nm and longer.

H series / high power (attenuated InGaAs)

  • High power measurements.
  • These detectors are more expensive and have slightly lower accuracy than normal InGaAs detectors, so only specify them if actually required.
  • Kingfisher power meters can be used up to the maximum display range.
  • The peak signal power must be within the meter range.
  • High power meters have less AutoTest sensitivity, which is a consideration for loss testing.
  • The KI2600-H5 offers the best balance for most high power users, with up to +24 dBm range & reasonable Autotestsenstivity

XL series / large area

  • POF, MPO and other fibers above 200u active light diameter.
  • Select from Si, Ge or InGaAs using the above guidelines. 
  • HCS is 200u core diameter, so a standard meter is just OK for HCS installers, but a large area detector gives laboratory grade results.
  • MPO connectors with 16 and 32 fibers require the larger Ge7 detector, which also works with other MPO fiber counts.
  • The KI2600XL-H3B offers the highest power level of +33 dBm.