NF488-15 notch band blocking negative filter

A notch filter, commonly known as a suppression filter, band stop filter, etc., is characterized by its ability to transmit most wavelengths with almost no loss, while specifying a frequency band (stopband) where light attenuation is significantly low. They are exactly the opposite of bandpass filters, which have high transmittance in the bandpass range and high cutoff outside the bandpass range, so they can only transmit light in a small wavelength range.

Compared to laser emission applications, notch filters are very important. It is very important to suppress the pump laser in order to achieve good signal-to-noise ratio in spectral experiments. In addition to spectrometers, notch filters are also commonly used in laser fluorescence instruments and biomedical laser systems.

Like all dielectric stack filters, the transmission and incident angle of the trap are related, and the center wavelength of the blocking region will shift towards shorter wavelengths as the incident angle increases; Ruicheng Optoelectronics“ The given transmission curve graph provides data on transmission rate and wavelength; …。

Ruicheng photoelectric notch filter is made by depositing a dielectric film on a polished glass substrate, which has excellent environmental stability. No matter which filter is chosen, the wavefront error of the emitted beam under vertical incidence is less than half of the wavelength of 633 nm. These filters are coated with an anti reflective coating on the back to ensure an average transmittance of over 90% on the passband.

Each filter is installed in an oxidized and blackened aluminum ring. Arrows indicate the design and propagation direction of light. By limiting scattering, the ring is easy to pick up and enhances the blocking light density. They can be installed on our filter frame and wheels. Due to the lack of threads on these mounting brackets, a 1-inch buckle is required to install the filter into the SM1 lens sleeve with internal threads. We do not recommend removing the filter from the installation ring as it may damage the filter. However, we also offer uninstalled and custom sized filters; For detailed information, please contact technical support.