A linear variable filter (LVF) coats a filter with spectral characteristics that change continuously in a line within a single substrate. By changing the position of the light incident on the filter, the transmission spectrum can be changed continuously.
The membrane design can be tailored to the target application and can be produced not only as a band-pass filter-type, but also as a long-pass filter or short-pass filter-type. The size of the linear variable filter can be set at will, and can be manufactured with a long side of 10 mm or less. Linear variable filters use high density metal oxide film, so they have high durability.
Applications
Color meters, light measurement, monochromators, etc.
Example of product
A linear variable filter that can be used in the visible light range (380-780nm).
A linear variable filter that can be used in the near-infrared region (900-1900nm).
Features
A notch filter removes only specific wavelengths and transmits light of other wavelengths. Wavelengths blocked by the notch filter can be set at will from a single wavelength to multiple wavelengths, and the wavelength range of ultraviolet, visible or infrared is not selected.
Advanced film design using multilayer dielectric film allows steep slopes to be realized to block specific wavelengths.
Notch filters, also known as band-stop filters, provide the opposite characteristics of band-pass filters, which transmit only specific wavelengths.
Applications
Laser light sources, laser Raman measurement, medical treatment, various analysis, etc.
Example of spectrum
A notch filter with a blocking performance of OD6 or higher at a specific wavelength (532 nm).
Notch filter with blocking performance of OD4 or higher at two specific wavelengths (550nm, 625nm).
Features
Hard-coated band-pass filters have excellent durability due to plasma-ion process coating.
Their characteristic is that the interference of reflected light generated at the interface of the thin film can be used to selectively transmit the desired specific wavelength.
Compared to absorbent filters such as glass and gelatin, this filter can restrict the transmission band narrowly and separate the transmission band sharply from the inhibition band, allowing extremely clear contrast characteristics to be obtained. With regard to inhibition performance, it is possible to support OD6 or higher in the visible region. The applicable wavelength range is from the ultraviolet region to the infrared region. Apart from that, we can also respond to requests for desired size, transmittance, inhibition band, etc.
Applications
LiDAR, 3D sensing, fluorescence analysis, Raman analysis, exposure apparatus, medical treatment, gas analysis, lasers, optical communications, astronomical observation, various sensors, etc.
Example characteristics
Narrow band-pass filter with a half value of 1 nm or less.
Standard band-pass filter in the visible light range.
Near-infrared region band-pass filter. We are also able to customize the inhibition band to block the full visible light range.
Definition of central wavelength
The definition of the central wavelength (λ0) of a band-pass filter can be divided broadly into the two following types. The type of soft coat band-pass filter differs depending on the product, so please use this as a reference. We design hard coated band-pass filters to meet customer requirements.
