Efficient Bandpass Filter with 850nm Wavelength for Security Use

The selection of optical filters is determined based on three core elements in the system optical path: first, the emission spectral characteristics of the light source.

When selecting a filter for an imaging system, it is necessary to ensure effective coupling between the filter's spectral transmission range, the sensor's response curve, and the spectral distribution of the illumination source.

The core difference between the two lies in their wavelength selection mechanism. Bandpass filters are designed to form a specific wavelength transmission window, allowing only light signals within this range to pass through, and implementing deep cutoff blocking for both short and long wavelengths on both sides of the window.

In laser excitation or laser detection systems, to suppress the submergence effect of incoherent ambient background light on signals, narrowband filters with a center wavelength precisely aligned with the laser line should be prioritized.

Fluorescence microscopy imaging systems rely on the efficient separation of excitation light and emission light. Its standard filter assembly includes three types: excitation filters, used to screen specific excitation wavelengths from a broad-spectrum light source.