Picowatt Photoreceiver PWPR


  • Ultra-low noise, NEP ≤ 10 fW/√Hz
  • Si and InGaAs models cover the wavelength range from 320 to 1700 nm
  • Bandwidth DC to 2 kHz
  • Transimpedance gain switchable 109 V/A, 1010 V/A
  • Free-space input 1.035″-40 threaded
  • Easily convertible to fiber optic input (FC and FSMA) with optionally available screw-on adapters
Photodiode1.2 mm Ø Si-PIN0.5 mm Ø InGaAs-PIN
Spectral Range320 – 1060 nm900 – 1700 nm
Bandwidth (−3 dB)DC – 2 kHzDC – 2 kHz
Rise/Fall Time (10 % – 90 %) 165 μs165 μs
Transimpedance Gain (switchable) 1 x 109 V/A 1 x 1010 V/A1 x 109 V/A 1 x 1010 V/A
Max. Conversion Gain 0.64 x 109 V/W (@ 900 nm, Gain 109 V/A) 0,64 x 1010 V/W (@ 900 nm, Gain 1010 V/A)1.1 x 109 V/W (@ 1580 nm, Gain 109 V/A) 1,1 x 1010 V/W (@ 1580 nm, Gain 1010 V/A)
NEP (@ 100 Hz) 9 fW/√Hz (@ 900 nm)10 fW/√Hz (@ 1580 nm)

Output voltage range up to +10 V. Offset adjustable by potentiometer. Output short-circuit protected. Power supply ±15 V via 3-pin Lemo® socket. A mating connector is provided with the device. Optional power supply PS-15 available. For further information please view the datasheet or contact FEMTO.

Measuring smallest optical signals from DC to 2 kHz

In addition to precise and fast cw-measurements the relatively large bandwidth from DC to 2 kHz also allows time-resolved and modulated measurements. Particularly the combination with lock-in amplifiers results in ultra-sensitive measurement systems being almost immune to disturbances from external sources. In this way the PWPR-2K can easily detect optical powers from about 100 fW up to 10 nW.

Compatible with optical bench (free space) and fiber optics

The PWPR-2K photoreceivers are factory equipped with an optical free-space input (FST) which is designed as a 1.035″-40 threaded flange with a screw-on coupler ring. It opens up a broad compatibility with optical accessories from various manufacturers, such as lenses, tubes, cage systems, optical adapters etc. The threaded FST input can be easily converted to an optical fiber input by screwing the optionally available fiber adapters (PRA-FC and PRA-FSMA) on it.

The relatively large-area detector facilitates optical focusing in free-space applications and ensures a high and stable degree of coupling when using the optionally available fiber optic adapter.

All PWPR-2K photoreceivers feature both UNC 8-32 and M4 tapped holes for mounting on metric and imperial threaded standard posts. The optionally available adapter plate PRA-PAP opens up further mounting options.


  • Spectroscopy, reflection and transmission measurements
  • Time resolved optical pulse and power measurements
  • Characterization of light sources
  • Highly sensitive applications using chopper modulation
  • Optical front-end for oscilloscopes, A/D converters and lock-in amplifiers

Related products / accessories

Power Supply


Post Adapter Plate