Fiber-coupled low coherence laser source with polarization-maintaining fiber cable



The Laser Diode Beam Source of type 51nano-S-808-19-G15-P-5-2-28-0-150 has a reduced power noise, a reduced coherence length and a low speckle contrast.
  • Reduced power noise: typ. < 0.1 % of Po (RMS, Bandwidth < 1 MHz)
  • Reduced coherence length: coherence length ≈ 300 µm
  • Reduced speckle contrast
  • Wavelength: 808 nm
  • Laser output power: 19 mW
  • Polarization-maintaining fiber cable
  • FC APC connector (8°-polish)
  • Modulation analog and TTL
  • With interlock and key switch (conform to EN 60825-1)
Alternative: Laser Diode Beam Source 51nano-N (OEM version w/o key switch and w/o interlock)


The fiber-coupled Laser Diode Beam Source of type 51nano-S-808-19-G15-P-5-2-28-0-150 has a reduced power noise (typ. < 0.1 % of Po (RMS, Bandwidth < 1 MHz)), reduced coherence length (≈ 300 µm) and a lowered speckle contrast

Electrical features
The output power is adjustable using a potentiometer or using the two modulation inputs for analog and TTL. 

Fiber cable
The source is fiber-coupled to a polarization-maintaining fiber cable (standard, polarization extinction ratio ≥ 23 dB). As a result the beam profile is rotationally symmetric with Gaussian intensity distribution. The fiber cable is equipped with an FC APC type connector (8°-polish). The fiber cable has a strain-relief and a protective sleeving (Ø 3 mm). Standard cable length is 150 cm.


  • Single-mode fiber 
  • Core-centered (single-mode only)
  • Multiple fiber output cables (51nanoC, single-mode only)
  • Other connector types including FC PC, DIN or AVIO, or E2000
  • Other fiber cable lengths
  • Incorporated vacuum feed-through

Laser safety
The laser safety is conform to IEC 825 / EN 60825-1. 

  • Interlock chain for the remote deactivation of the laser
  • Laser power-up is only possible using the key switch
  • LED status indicator for “Laser ON”
  • For a quick start the laser is shipped with a interlock connector type BC0106F-iLCK

An OEM version is available as type 51nano-N without key switch or interlock which is not conform to EN 60825-1. 

Low coherence fiber coupled laser 51nano

Technical data


Order Code
Will replace
Laser class
Center wavelength
808 ± 10 nm
0.7 - 4 nm
Output power
typ. 19 mW
Power adjustment
< 1 - 100 %
typ. < 0.1 % of Po (RMS, BW < 1 MHz)
≈ 300 µm
Fiber cable
Fiber type
0.077 ± 10 % (1/e2)
6.7 µm ± 10 % (1/e2)
≥ 23 dB
Fiber cable length
1.5 ± 0.05 m (standard)
Ø 3 mm with Kevlar strain-relief
FC APC (standard)
Power stability
max. 12 % power variation between 15°C and 35°C
Electronics type
Electr. cable length
1.5 ± 0.1 m (standard)
Supply voltage
5.0 ± 0.2 V
Max. current consumption*
260 mA
Modulation input connector
Modulation inputs
Max. input voltage
5 V
5 V
Voltage for Pmin / PO
< 0.8 V / > 2.4 V
0 V / 2.5 V
Input impedance
22 kOhm
22 kOhm
Max. modulation frequency
100 kHz
100 kHz
Time delay ON/OFF*
1.5/0.1 µs
2/0.3 µs
Rise / fall time*
1.0/1.0 µs
1.0/1.0 µs
* Typical value. Depends on laser diode.
Operating temperature
15 - 35°C ± 0.5°C
Warm-up time
approx. 10 min
Air humidity
max. 90 % non-condensing
530 g
50 x 58 x 166 mm
Protection Class

Dimensions (for a complete dimensional drawing please refer to the downloads section)

Low coherence fiber coupled laser 51nano


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Power Supply 5 V
Interlock connector
Fiber Collimators single-mode/PM

Fiber Collimators for collimating light exiting a single-mode or polarization-maintaining fiber cable