Dual bandpass filter

A dual bandpass filter refers to a single filter that has two bandpass filters. Only one filter is used to capture two specific bands, allowing for the selection of two or more bands to pass through. The dual bandpass filter has high peak transmittance and deep cutoff, effectively suppressing halo and temperature drift, and expanding the application of the filter. Usually used in fields such as security monitoring, machine vision inspection, and intelligent transportation, especially in drone monitoring, dual band filters are becoming increasingly widely used.

For example, using a flame photometric detector to detect the content of sulfur and phosphorus. When sulfur or phosphorus containing compounds burn in a hydrogen rich flame, they generate chemiluminescent substances that emit characteristic wavelengths of light. By recording these characteristic spectra, sulfur and phosphorus can be detected. When the excited state S2 * molecule returns to the ground state, it emits 350 ^ -; The characteristic spectrum of 430nm (blue purple) corresponds to a maximum intensity at a wavelength of 393nm. Phosphorus containing compounds generate phosphorus oxides during combustion, which are reduced to chemiluminescent HPO fragments by hydrogen in a hydrogen rich flame. When the HPO fragments return to the ground state, they emit characteristic green light (wavelength of 480-560nm, maximum intensity corresponding to a wavelength of 526nm). The content of the measured components of these two characteristic lights is directly proportional to the light intensity, which is the quantitative basis of flame photometric detectors. Therefore, flame photometric detector filters are usually classified into sulfur and phosphorus types.

Traditional flame photometric detectors can only measure the content of one element at a time, while by using dual bandpass filters, sulfur and phosphorus can be detected simultaneously, eliminating the need for frequent filter switching and making detection more efficient.

Ruicheng Optoelectronics produces dual bandpass filters that are coated with a hard film, durable and easy to handle. The single filter with two bandpass filters can greatly enhance fluorescence imaging and can be easily set up for various fluorescence applications. Each dual bandpass filter provides high average transmittance and excellent cutoff. This can generate maximum brightness and contrast in any application. Dual band filters are an ideal choice for simultaneously viewing multiple fluorescent groups.