Fiber-coupled low coherence laser source with single-mode fiber cable (OEM version)



The Laser Diode Beam Source of type 51nano-N-980-2.3-TH4-P-5-2-18-0-150 has a reduced power noise, a reduced coherence length and a low speckle contrast.
  • Reduced power noise: typ. < 0.25 % of Po (RMS, Bandwidth < 1 MHz)
  • Reduced coherence length: coherence length ≈ 300 µm
  • Reduced speckle contrast
  • Wavelength: 980 nm
  • Laser output power: 2.3 mW
  • Single-mode fiber cable
  • FC APC connector (8°-polish)
  • Modulation analog and TTL
  • OEM version w/o interlock and w/o key switch
Alternative: Laser Diode Beam Source 51nano-S (with key switch and interlock) or with single-mode fiber cable


The fiber-coupled Laser Diode Beam Source of type 51nano-N-980-2.3-TH4-P-5-2-18-0-150 has a reduced power noise (typ. < 0.25 % 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 asingle-mode fiber cable. 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.


  • Polarization-maintaining 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
This OEM version has no key switch or interlock and is not conform to EN 60825-1.
It can be operated conform to EN 60825-1 by using a switchbox.
As an alternative, a version with key switch and with interlock (conform to EN 60825-1) is available
as type 51nano-S

Low coherence fiber coupled laser 51nano-N

Technical data


Order Code
Will replace
Laser class
980 ± 10 nm
Band width
0.7 - 4 nm
Output power
typ. 2.3 mW
Power adjustment
< 1 - 100 %
typ. < 0.25 % of Po (RMS, BW < 1 MHz)
≈ 300 µm
Fiber cable
Fiber type
0.093 ± 10 % (1/e2)
6.7 µm ± 10 % (1/e2)
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 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


000824000400.pdf (Dimensional drawing)
000829000900.stp (STEP model)
000829000900.stp (STEP model, for registered users only)

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Power Supply 5 V
For laser diode beam sources of electronics type S/C/P/H and 5 V power supply

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