SuperK VARIA tunable filter

The SuperK VARIA is a cost effective and flexible alternative to a monochromator, effectively turning the SuperK supercontinuum laser into a powerful single-line laser with a 440 nm tuning range and variable bandwidth. The center wavelength of the pass band can be tuned anywhere between 400 and 840 nm and the bandwidth is variable between 10 and 100 nm, making the SuperK VARIA the most flexible filter solution on the market.


Normalized transmission versus wavelength

  • 400 – 840 nm wideband coverage
  • 10 – 100 nm variable bandwidth, for higher power and reduced speckle
  • >50 dB suppression of out-of-band light
  • High transmission (no polarization loss)
  • Handles high average power
  • Single-mode fiber delivery
  • Available with Power Lock active output power stabilization
  • Fully computer controlled

Increasing the bandwidth of the filter has the added advantages of higher power throughput and reduced speckle in imaging applications. Moreover, high out-of-band suppression of up to 50 dB makes the SuperK VARIA an ideal tool for FLIM and other applications using high sensitivity detectors.

The SuperK VARIA is designed to be used with the SuperK supercontinuum sources, but can also be used with traditional laser systems or broadband light sources. Use the collimated free-space output from the filter directly or combine the VARIA with the SuperK CONNECT broadband fiber delivery system for pristine single-mode fiber delivery over the entire tuning range in one single fiber.

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Power Lock

The Power Lock options enables you to lock the power output of the SuperK VARIA via a build in photo detector. Simply connect the detector to the External Feedback BNC connector of the SuperK. Activate locking from the control panel and the SuperK will now lock the power output of the VARIA. The long term stability of a locked output will typically be better than +/- 0.5 % (over many hours) - depending on the wavelength.

Get more information in our application note on Power Lock

Single mode fiber delivery

The SuperK VARIA is compatible with our SuperK CONNECT high performance fiber delivery system that comes complete with broadband fibers and a range of termination options such as FC/PC connectors or high quality collimators. Interfacing is handled by the CONNECT fiber coupling block that ensure easy and stable single-mode coupling that can be disconnected and reconnected without alignment.

SuperK CONNECT fiber delivery system


Wavelength tuning range 400 – 840 nm
Minimum bandwidth  FWHM < 10 nm
Maximum bandwidth FWHM 100 nm
Transmission through the module  (Average in 50nm bandwidth) 70-90 % (Un-polarized)
Upper out of band suppression (10nm above upper FWHM transmission wavelength in 400-900 nm range)* > 50 dB
Lower out of band suppression (10nm below lower FWHM transmission wavelength in 400-900 nm range)* > 40 dB
Output Polarization Un-polarized or P-Polarized (adding output polarizer)
Tuning speed > 10 nm/s
Repeatability of wavelength position** < 0.2 nm
Absolute wavelength accuracy +/- 5 nm
Wavelength temperature sensitivity < 0.05nm/deg
Transmission temperature sensitivity < 0.2 %/deg
Interlock Collimator, lead
Output mode Collimated free-space or SuperK CONNECT with FC-APC

* With SuperK CONNECT single-mode fiber delivery
** With collimator inserted. The wavelength position may shift if the collimator is removed and reinserted.


Weight 7.9 kg
Dimensions (LXBXH) 272 mm X 211.5 mm X 67.6 mm
Electrical interface SuperK BUS interface
Analog feedback signal


Operating temperature range 15-30 °C
Storage temperature range 5-50 °C (non condensing)
Humidity 20-80 % RH
SuperK VARIA mechanical drawing top view SuperK VARIA mechanical drawing front view