Visible light dichroic mirror is an optical component designed based on the principle of light interference, which can selectively reflect or transmit specific colors of light according to its wavelength. It is widely used in optical systems for precise control of the visible spectrum range (about 380nm-780nm).
working principle
A dichroic mirror is usually composed of multiple layers of dielectric thin films, and the thickness and refractive index of each layer are precisely designed. When light is incident, different wavelengths of light produce phase differences due to interference effects, causing some wavelengths to be strongly reflected while others are efficiently transmitted. For example:
Long wave pass type: Reflects short wavelength light (such as blue violet light) and transmits long wavelength light (such as red light).
Shortwave type: Reflects long wavelength light and transmits short wavelength light.
Bandpass type: Only allows a narrow band to pass through, with the rest reflecting.
This characteristic makes it extremely critical in scenes where separation or merging of light paths is required.
Main application areas
Projection and Display Technology
In DLP or LCD projectors, multiple dichroic mirrors are used to separate white light into the three primary colors of red, green, and blue, and recombine the light before imaging to enhance color saturation and light efficiency.
Fluorescence microscope system
Used to separate excitation light and emission fluorescence signals, ensuring that only specific wavelengths of fluorescence reach the detector, improving image contrast and clarity.
Stage lighting and illumination
Realize dynamic color mixing and adjustment, enhance visual expression, while reducing the frequency of color filter replacement and improving system stability.
Spectral Analysis and Scientific Instruments
As a spectral element, the polychromatic light is decomposed into different bands in the spectrometer for subsequent detection and analysis.
Laser system
Used for beam combining or multi-color laser output, such as achieving precise superimposition of three colored light in RGB lasers.
performance advantage
High reflectivity (>99%) and high transmittance (>97%) reduce energy loss.
Extremely low absorption and scattering, avoiding thermal accumulation, suitable for high-power laser environments.
The film layer is stable, wear-resistant, corrosion-resistant, and has a long service life.
