Kent Optronics
polarizer-free tunable notch filter

The NP-TNF series, representing the most advanced tunable notch filter product in the category, is a polarizer-free tunable notch filter made from Kent Optronics proprietary liquid crystal materials.

Data Sheet


The NP-TNF series is a polarizer-free tunable notch filter made from Kent Optronics' proprietary liquid crystal materials. The NP-TNF provides the most agile means for light spectral notch. The notch wavelength of a single NP-TNF, with a bandwidth of a few tens to hundreds of nanometers, can be electrically tuned across a broad spectral region from 300 to1000 nm in the visible and infrared for light blocking or routing.

The product series provides customers with an excellent E-O component for serving as a tunable laser beam director, laser blocker, beam splitter, etc… in the envisioned photonics systems, such as laser protection devices, remote sensing, spectral imaging, vision-aid devices, and broadband light routing.

As compared to the state-of-the-art tunable notch filters, the NP-TNF series offers the following unprecedented performance specifications:

  • Much broader tuning range over 300 to 1,000nm,
  • high optical density (OD) at the notch wavelength
  • >80% out band transmittance, and
  • <0.5 ms/nm tuning speed

The product comes with a compact power supply that can be either battery or 110/220 V wall-plug powered. Customers have the options to choose the filter substrate material, shape, aperture, pixel format and the operation mode (i.e., manual or computer controlled). All products are offered at a competitive price. Contact us for a price quote with your specific application requirements.

np-tnf spectrum

np-tnf contrast

NP-TNF™ Spectrum (SWIR)

NP-TNF™ Contrast Ratio (SWIR)

NP-TNF™ Specifications

Spectral region 0.4-2.7 µm
Out notch band transmittance ~80%
Polarization properties Polarization insensitive
Tuning range 30-1,000 nm (continuously tunable blocking)
Repeatability and precision <±1 nm
Tunable narrowband blocking optical density OD>3 over the bandwidth
Angular range for broadband transmission (parallel light operation) >25° in air
Angular range for tunable narrowband blocking (parallel light operation) >25° in air
Spectral bandwidth 50-300 nm
Spectral uniformity <2 nm
Clear aperture Diameter: 5-50 mm (circular)
Area: 5x5 to 50x50 mm² (square)
Thickness <10 mm
Operating temperature range -5°C (23°F) to 55°C (131°F) without heating mechanism;
-40°C (-40°F) to 55°C (131°F) with heating mechanism
Survival temperature range -51°C (123.8°F) to 120°C (248°F)
UV stability Stable under UV-B at 40mW/cm² for 3000 hours
Laser damage threshold >1 J/cm² (5ns pulsed @ 532nm)
>1 kW/cm² (CW @ 532nm)
Uniformity of retardance <0.1 OD across the clear aperture
Wavefront distortion <0.5 wavelength at 633 nm
Parallelism <2 arcminutes
Tuning speed <0.7 ms/nm
Rate of change of temperature Survives a rate of change of temperature of 3°C per minute
Driving voltage Up to 350V
Computer interface USB interface w/ PC
Weight <100g (filter only)
Substrate material Glass, quartz, and plastic (PC)
Cable length 1 m
Input power to the driver 110V or 220V/50-60Hz AC or 9V battery
Filter power consumption <6mW/cm²
Power supply weight 200g