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200 MHz Variable Gain Photoreceivers

  • Adjustable transimpedance gain from 102 to 108V/A
  • Wide bandwidth up to 200 MHz
  • Various Si and InGaAs models cover the 320 to 1,700 nm wavelength range
  • High dynamic input range up to 10 mW optical power
  • Large optical detector size up to 3 mm dia.
  • Very low noise, NEP down to 88 fW/√Hz
  • Switchable low pass filters for minimizing wideband noise
  • Fiber optic and free space input
  • 1.035″-40 threaded free space input compatible with many optical standard accessories


The OE-300 photoreceiver consists of a premium quality photodiode followed by a high-end, variable gain transimpedance amplifier. The low noise performance (NEP) is outstanding and sets a benchmark for wideband photoreceivers particularly in the high and mid-range gain settings. The relatively large sized detectors make optical alignment easy and also ensure a very high coupling efficiency when using the Si models together with the optionally available fiber optic adapters PRA-FC/SMA.

The switchable gain from 102 to 108 V/A (decade increments) allows precise and reliable measurements within a very wide dynamic range from nanowatts up to 10 milliwatts optical power.

Many additional features like switchable low-pass filters, offset adjustment, switchable AC/DC coupling and the capability of manual and opto-isolated remote control by a PC make the OE-300 the most versatile wideband photoreceiver in its class.


The Si-models are factory equipped with an optical free space input. There is the choice between a 1.035″-40 threaded and a 25 mm unthreaded flange. Both types offer a broad compatibility with optical standard accessories like tubes, lenses, cage systems, optical adapters etc. from various manufacturers. The threaded free space input e.g. can be easily converted to an optical fiber input by screwing a 1.035″-40 externally threaded fiber-adapter to it.

For the InGaAs models there is the choice between a fixed fiber input (FC) model allowing highly accurate fiber optic measurements and a model with free space input (1.035″-40 threaded and 25 mm unthreaded flange available).

Fiber Adapters:  FC  |  FSMA

  • Compatible with all FEMTO photoreceivers with threaded 1.035”-40 free space input
  • Easy mounting option for standard optical fibers
  • Recommended for photosensitive areas of 0.4 mm diameter or more

All the OE-300 models can be easily mounted to standard M4 and 8-32 UNC threaded optical post holders via the optionally available post holder adapter type PRA-PAP.


  • All purpose low-noise photoreceiver (O/E converter) for the MHz range
  • Time resolved optical pulse and power measurements
  • Laser intensity noise measurements (RIN)
  • Optical front-end for oscilloscopes, spectrum analyzers, A/D converters and RF lock-in amplifiers
Detector Size (mm)1.0 x 1.0 Ø 3.0Ø 0.08Ø 0.3
Spectral Range400-1000 nm320-1000 nm900-1700 nm800-1700 nm
InputFree Space
fiber adapters available
Free Space
fiber adapters available
FC fiberFree Space
NEP (Dependent on Gain Setting)[/√Hz]140 fW - 377 pW154 fW - 340 pW88 fW - 217 pW93 fW - 219 pW

The following characteristics are valid for all models:

Performance RangeLow NoiseHigh Speed
Gain Setting [V/A]
Bandwidth [- 3 dB] [MHz] 200
Rise Time (10%-90%)1.83 ns
(3.5 ns)1
4.4 ns
(5.8 ns)1
25ns0.1 μs0.2 μs1.6 μs2.0 ns
(3.5 ns)1
4.4 ns
(5.8 ns)1
25 ns0.1 μs0.2 μs1.6 μs
Gain Accuracy±1 % (transimpedance)
Low Pass Filterswitchable to 1 MHz and 10 MHz
Output Performance±1 V (@ 50 Ώ load), for linear amplification
Power Supply±15 V, +150 mA/-100 mA typ., ±200 mA recommended
Control Interface5 opto-isolated digital inputs, TTL/CMOS compatible, analog offset control voltage input
Interface Software OptionLUCI-10 Control Interface Software and Hardware option
Case170 x 60 x 45 mm (L x B x H), weight 320 g (0.74 lb.)
1 model OE-300-SI-30

Offset adjustable by trimpot or external control voltage. LED overload indication. Output short-circuit protected. Power supply via 3-pin LEMO socket. A mating connector is provided with the device. Optional power supply PS-15 is available.

FEMTO Product Catalog

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