Home > Filters > 14NOF - Precision Type Reflective Notch Filters
Based on reflective Volume Bragg Gratings (VBG)
Suitable for Ultra-low Frequency Raman Spectroscopy
Ultra Narrow Rejection Bandwidth (<10 cm-1)
Measurements of both Stokes and anti-Stokes modes
No degradation in high power light
Environmentally stable: high temperature operation, no humidity effects
No polarization dependence
14NOF Notch Filter is a reflective Volume Bragg Grating recorded in a bulk of photosensitive silicate glass.
Ultra-Narrow-Band Notch Filters reflect light with bandwidths as narrow as 5 cm-1 while all other wavelength pass unaffected with up to 95% total transmission.
14NOF's enable simultaneous measurements of Stokes and Anti-Stokes Raman bands down to 5 cm-1 with a single stage spectrometer.
Our Notch filters can withhold temperatures of up to 400° C and are fully environmentally stable with a practically unlimited life-time.
Central wavelengths of the filters can be angle tuned by several nanometers without reduction of the filter optical density.
6 ± 1°
- 6 ± 1°
Blocking of Design Wavelength:
OD>3: > 99.9% OD>4: > 99.99%
2.5 ± 1 mm
Spectral Bandwidth, FWHM:
< 0.4 nm
Internal Transmittance at 633 nm:
OD>3: 11 mm x 11 mm (CA> 85%) OD>4: 12.5 mm x 12.5 mm (CA>85%) OD>3: 12.5 mm x 12.5 mm (CA> 85%) OD>4: 11 mm x 11 mm (CA>85%)
Broadband, R < 0.5% per surface
Mounted in Ø25 mm ring
LA models of polymer
Semiconductor lattices and nanostructures
Spectral profiles of the narrowest thin film filter available on the market and
Notch Filter (14NOF). The bandwidth of a typical 14NOF is about 100-200 pm, whereas bandwidth of TF filters can't be narrower than 2-3 nm.
Optical density of single 14NOF is limited to about OD4 and, thus, to provide
sufficient Rayleigh light suppression depending on the measurement
wavelength 2 to 3 filters have to be used in sequence.
14NOFs are mounted
in Ø25 mm round aluminum holders for easy use with standard optomechanical assemblies
Product selection guide
Grating Aperture, mm: 11 x 11
Grating Aperture, mm: 12.5 x 12.5
Custom designed 14NOF - Precision Type Reflective Notch Filters are available upon request with the following specifications:
Attenuation: > 99.99% (OD4+)
Spectral bandwidth (FWHM): 5-8 cm-1
Operating range: 400-2500 nm
Thickness: 2-4 mm
Apertures: up to 25 x 25 mm2
Angular selectivity: 2-10 mrad
Incident/Diffracted Angles: 0-45°
Transmittance: up to 95%
Transmission ripple: <1% at ±0.5 nm from laser line (@633 nm)