Multi bandpass filter
At present, coated filters have been widely used in optical instruments, optical communication, optical remote sensing and other fields, becoming an indispensable component of the optical industry. With the development of the first optical industry, the requirements for thin film filters are also increasing. In addition to high precision and reliability, some special functional filters have also emerged. One new development direction is multi-channel bandpass filters, abbreviated as MPF in English. The so-called multi-channel bandpass filter, as the name suggests, refers to a filter with more than one passband compared to traditional bandpass filters, where a single filter has multiple passbands. Obviously, if its channel number is N, the information it carries is N times that of a single bandpass filter. For the whole machine, the number of filters required to carry the same amount of information cloud is 1/N of that of traditional filters. Therefore, when carrying the same information, using MPF can simplify the optical system of the whole machine and reduce its load, which is undoubtedly a great blessing for space optical instruments. In fact, it is the integration and lightweight development of space optical payloads that have led to the emergence and development of multi-channel bandpass filters, which have been applied to other fields. This multi bandpass filter has high peak transmittance and deep cutoff, effectively suppressing halo and temperature drift, and can produce maximum brightness and contrast in any application. Multi bandpass filters mainly include dual bandpass and triple bandpass filters.
According to the principle of designing multi bandpass filters, they can be divided into MPF based on Fabry Perot standards and MPF based on multi-layer composite films.
The difference between multi bandpass filters and negative filters:
Negative filters are typically used to cut off or reflect specific wavelengths, through which both sides of the spectral wave can be transmitted. Its usage method and spectral curve are opposite to bandpass filters. This product is produced using a dielectric hard film with the help of vacuum ion assisted coating, resulting in high density, no drift, resistance to wiping, and resistance to moisture erosion of the film layer. An anti reflective film is added to the back to improve transmittance and increase light energy. Negative filters are mainly used in laser protection, Raman spectrometers, laser fluorescence analyzers, biomedical laser systems, and astronomical filters.
Multi bandpass filters can select two or more frequency bands to pass through, and are generally used in fields such as intelligent transportation, safety monitoring, and machine vision inspection.
In the field of fluorescence detection, the application of dual band filters is becoming increasingly widespread, with the following characteristics:
1. A single filter has multiple bandpass filters;
2. Provide high peak transmittance and excellent cutoff;
3. Very suitable for simultaneously viewing multiple fluorescent groups;
4. Suitable for optical performance with multi sided fluorescent dichroic filters.
According to the principle of designing multi bandpass filters, they can be divided into MPF based on Fabry Perot standards and MPF based on multi-layer composite films.
The difference between multi bandpass filters and negative filters:
Negative filters are typically used to cut off or reflect specific wavelengths, through which both sides of the spectral wave can be transmitted. Its usage method and spectral curve are opposite to bandpass filters. This product is produced using a dielectric hard film with the help of vacuum ion assisted coating, resulting in high density, no drift, resistance to wiping, and resistance to moisture erosion of the film layer. An anti reflective film is added to the back to improve transmittance and increase light energy. Negative filters are mainly used in laser protection, Raman spectrometers, laser fluorescence analyzers, biomedical laser systems, and astronomical filters.
Multi bandpass filters can select two or more frequency bands to pass through, and are generally used in fields such as intelligent transportation, safety monitoring, and machine vision inspection.
In the field of fluorescence detection, the application of dual band filters is becoming increasingly widespread, with the following characteristics:
1. A single filter has multiple bandpass filters;
2. Provide high peak transmittance and excellent cutoff;
3. Very suitable for simultaneously viewing multiple fluorescent groups;
4. Suitable for optical performance with multi sided fluorescent dichroic filters.