FEMTO Messtechnik GmbH Photoreceivers - Choices of High speed and Low Noise Si and InGaAs PINs

14 Dec 2017

When it comes to selecting a photoreceiver for measuring fast and small optical signals FEMTO
has plenty of options. All versions include the choice of an integrated Si or InGaAs PIN photodiode.
Here’s a run-down on their receiver options:

FWPR Ultra High Sensitivity and Very Low Noise

This femtoWatt photoreceiver combines selected PIN diodes with a specially designed transimpedance amplifier, providing gain up to 1012 V/A and ultra-low noise with an NEP of 0.7fW/√Hz @ 960nm (for Si) and 7.5fW/√Hz @ 1550nm (for InGaAs). It is possible to measure directly optical powers as low as 50fW without any further averaging circuitry. Applications include photon counting, NIR spectroscopy, fluorescence, electrophoresis and chromatography.

LCA Low Noise Current Amplifier with 107 V/A Transimpedance Gain

FEMTO combined their proven and outstanding low noise current amplifiers with state of the art photodiodes resulting in a minimum NEP as low as 75fW/√Hz that allows for detection of optical signals in the nanoWatt range without further averaging. Applications include general purpose opto-electronic
measurements, optical front-ends for oscilloscopes, A/D converts and lock-in amplifiers.

HCA-S High Sensitivity and High Bandwidth

Utilising high speed photodiodes and FEMTO’s HCA series amplifiers, this series offers gain up to 1.9x104 V/A at 1550nm (for the 200MHz model) and 4.8x103 V/A at 1550nm (for the 400MHz model). The sophisticated DC coupled multistage amplifier design permits 1.8ns rise time measurements when using the 200MHz model and 1ns rise time with the 400MHz model, with NEP of 40pW/√Hz (at 800nm and 100MHz) and 24pW/√Hz (at 1550nm and 100MHz). Optical signals in the microWatt range can be detected.

HSPR-X and HSA-X-S GigaHertz Technology

Here FEMTO combine their GHz amplifiers with state of the art photodiodes to produce photoreceivers with remarkable performance. The HSPR-X and HSA-X-S offer ~2 GHz bandwidth, with an NEP of 11pW/√Hz at a transimpedance of 5x103 V/A. MicroWatt optical power levels in the GHz range can be measured.

OE-200 Variable Gain

Designed for a wide range of applications requiring fast 500MHz
from DC measurement of small optical signals, adjustable gain from 103 to 1011 V/A offering
measurement between ~100fW to 2mW optical input power. This high sensitivity is achieved using a
low noise design resulting in an NEP of 6fW/√Hz. Additional features include switchable signal filters
and opto-isolated remote control by PC.

OE-300 Variable

Gain Similar to the OE-200 however this model offers DC to 200MHz
measurement in order to incorporate large aperture photodiodes when using either free space optical
beams or aligning fibre optic couplers. Switchable gains from 102 to 108 V/A allows for dynamic
range measurement of 10mW optical power.

More Information http://www.lasercomponents.com/uk/measurement-devices/amplifier/photoreceivers/