Koheras BASIK single-frequency line card lasers

The Koheras BASIK single-frequency fiber lasers are the pinnacle of industrial low noise Erbium and Ytterbium lasers. The lasers have ultra-low phase noise and Hz-range linewidth normally only found in costly scientific systems. Based on a truly single-mode DFB fiber laser architecture, they offer ultra-stable performance free of mode-hops, and with unrivaled reliability.

Koheras BASIK single frequency fiber laser line card


  • ­ Ultra-low phase noise and narrow linewidth
  • ­ Stable single-frequency operation
  • ­ Industrial OEM packaging
  • ­ Designed for Multi-channel systems (ACOUSTIK) or stand-alone
  • ­ Integrated fast wavelength modulation (optional)

This range of lasers is offered as compact modules typically for industrial OEM integration. It is also designed as a building block for our ADJUSTIK benchtop systems and the ACOUSTIK multi-channel systems. It is supplied with NKTP CONTROL software for the control and read-out of laser parameters on a PC such as wavelengths, output power, and RIN suppression.

Any interferometric use that requires high-frequency stability or a long coherence length will benefit from this type of laser technology. The typical applications are remote sensing, including seismic sensings, such as oil and gas exploration and exploitation, security (perimeter and pipeline detection), and structural pipeline monitoring.

Furthermore, the low-intensity noise of the lasers combined with the high spectral stability makes them ideal as sources for wind LIDAR systems used for the wind turbine and aerospace industry, as well as for interferometry laser vibrometry sensing systems.

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Laser models

Model Standard Wavelength Other wavelengths Output power PM Fast modulation
X15 1550.12 nm 1535 - 1580 nm 30 mW 1) Yes Yes
E15 1550.12 nm 1535 - 1580 nm 40 mW 1) Optional Optional
C15 1550.12 nm 1535 - 1580 nm >10 mW Optional Optional
Y10 1064.00 nm 1030 - 1120 nm > 10 mW Yes Yes

1) Adjustable output power.

C15: Is a co-doped Erbium/Ytterbium fiber laser for operation in the 1535-1580 nm wavelength range offering the lowest intensity noise (RIN) and is a shot-noise limited fiber laser.

X15/E15: Is an Erbium-doped fiber laser for operation in the 1535-1580 nm wavelength range offering the lowest phase and frequency noise and narrowest linewidth of the entire laser portfolio. It is often deployed for interferometric sensor or remote sensing applications, such as Distributed Acoustic Sensing (DAS), demanding 10s of kilometers of coherence length and ultra-high frequency stability.

Y10: Ytterbium-doped fiber laser system for operation in the 1030-1120 nm wavelength range with narrow linewidth and low-intensity noise. This laser is commonly used for laser stabilization, atomic physics, metrology, spectroscopy, fusion energy, general replacement of conventional Nd:YAG lasers, and many other applications.

Tuning and PM Options

  • PM operation: The output of the BASIK fiber laser is per default single-mode fiber, however, we always offer a PM (Polarization Maintaining) option to ensure a fixed orientation of the polarisation. This may be required whenever the laser output needs to be externally modulated or frequency-converted.
  • Thermal wavelength tuning: The Koheras fiber laser systems are by default thermally tunable to enable the user to match and stabilize the laser at a certain wavelength.
  • Fast wavelength tuning: This feature can be offered for applications demanding higher wavelength stability than provided by the free-running laser. It enables the laser e.g. to be locked to an external reference such as an atomic transition line or interferometer.


Model X15 E15 C15 Y10
Laser emission CW - inherently single frequency
Beam quality [M²] < 1.05 < 1.05 < 1.05 < 1.05
Linewidth [kHz] 1) < 0.1 < 0.1 < 15 < 20
Max phase noise


-105@1 Hz
-125@10 Hz
-130@100 Hz
-128@1 kHz
-90@10 Hz
-110@100 Hz
-130@20 kHz
-69@10 Hz
-89@100 Hz
-109@20 kHz
Max phase-noise [(µrad/√Hz)/m] 3.1 @1 Hz
0.6@10 Hz
0.3@100 Hz
0.4@1 kHz
32@10 Hz
3.2@100 Hz
0.3@20 kHz
355@10 Hz
36@100 Hz
3.5@20 kHz
RIN peak [MHz] app. 0.7 app. 0.7 app. 1 app. 1.5
RIN level @ peak / 10 MHz [dBc/Hz] <-100 / <-135 <-120 /<-140 <-105 /<-140
Optical S/N (50 pm res.) [dB] > 50 (typ. > 55) 2) > 50 (typ. > 55) 2) > 65 (typ > 70)
Min thermal wavelength tuning range [pm] 3) +/- 125 +/- 350 +/- 350 +/- 240
Total thermal tuning range [pm] 350 1000 1000 680
Fast wavelength modulation range [GHz] 4) 0.5 8 8 10
Fast wavelength modulation [kHz] 4) Up to 20
PM output - PER [dB] 4) > 23
Monitor optical output FC/APC

1) Lorentzian
2) >47 dB (typ. > 52 dB) for non-PM version
3) Relative to center wavelength at room temperature. If the laser is operated in very cold or hot environments, this wavelength range is truncated on either the upper or lower side.
4) Default for X15 and Y10.

Mechanical / Electrical/Environmental

Power supply requirements [VDC] 12
Power consumption [W] Typical 4, max 12
Electrical interface 30 pin DIN41612 male
Fast modulation drive voltage Differential 2x5 V with common-mode voltage at 2.5 V
Connectors Standard: FC/APC pigtailed
Option: Bulkhead/pigtailed FC/APC, SC/APC
Monitor output Optional
Dimensions (HxWxD) [mm] 22.5x91.2(111)x220
Weight [kg] 0.6
Operating temperature range, module temperature [°C] 15 - 60
Storage temperature [°C] -20 - 60
Humidity non condensing [%RH] 0-70
Koheras BASIK X15 mechanical drawing
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