TOPTICA Photonics AG - A passion for precision -

COOL (constant optical output level)

Hands-off solution for fiber-coupled diode lasers

The COOL technology (Constant Optical Output Level) is TOPTICA´s unique solution for high power single-mode hands-off permanently fiber coupled lasers.Aligning and focusing a laser beam into ultra tiny single mode fibers (down to core diameters of 2.5 µm) with highest efficiency is utmost challenging: Laser pointing fluctuations, deviations in the beam path and smallest thermal or mechanical drifts in the fiber mounting can all contribute to significant loss of fiber coupling efficiency. Up to now in many cases manual realignment by a trained person was required from time to time to recalibrate the laser output power.

TOPTICA´s COOL patent pending fiber coupling concept is new, because it does not use any mechanical micro adjustable parts, which normally are the first to move due to thermal or mechanical influences.All major optical components are solidly mounted and the optical micro alignment is unsusceptible to mechanical and thermal distortions or translations.

  • Schematic of COOL-AC Technology
  • Schematic of COOL-DC Technology

Two versions of the COOL technology are available:


  • DuraCalibrated solution for compact OEM diode lasers (integrated in the iBeam smart PT)
  • Factory set to permanent fiber coupling efficiency of higher than 50%
  • Unsusceptible to thermal fluctuations between 15 and 35 °C
  • Unsusceptible to extensive mechanical disturbances
  • Drop shipment warranty: Laser immediately in spec after unpacking


  • All basic features like COOLDC
  • Additional AutoCalibration Feature
  • Fiber coupling values of higher 50 % can be restored by single push button command
  • Ideally suited for complex multi laser solutions, i.e. the iChrome MLE
  • Drop shipment warranty: Laser in spec after push button command