How does an optical bandpass filter work?
An optical bandpass filter is an optical component that transmits a specific range of light wavelengths while blocking the other wavelengths of light.
Key Characteristics
- Center Wavelength: This is the specific wavelength at which the filter is designed to transmit the most light. It is the midpoint of the filter's transmission band.
- Full Width at Half Maximum (FWHM): Also known as the bandwidth, FWHM represents the range of wavelengths effectively transmitting the light. (50% of the peak transmission)
- Blocking Level: It indicates how well the filter can eliminate unwanted wavelengths outside its passband. (Specified with OD, Optical Density)
- Peak Transmission: This is the maximum percentage of light that can pass through the filter around its central wavelength. A filter with a peak transmission of 90% at its center wavelength means that 90% of the incident light at that wavelength will be transmitted.
How does Optical Bandpass Filter Work:
Optical bandpass filters are often constructed using multiple thin film layers or optical materials. When light enters the filter, the design of these layers, including their thickness and refractive index, causes specific wavelengths to experience constructive interference, allowing them to pass through. At the same time, other wavelengths undergo destructive interference and are either absorbed or reflected by the filter.
Interactive Demo for Bandpass filter
This interactive web app is an Optical Bandpass Filter Interactive Demo. It's designed to let users explore how an optical bandpass filter affects the output spectrum by adjusting key parameters and light sources.
https://syronoptics.github.io/bandpassFilterInteractiveDemo/
