기능

• Tungsten lamps and halogen lamps emit hot rays (infrared rays) along with visible light, which can raise the temperature of the irradiator.
• A cold filter transmits visible light and attenuates infrared light, thereby preventing the temperature of the irradiator from rising.
• By combining the rapid decay of transmittance from the visible to the near-infrared, which is characteristic of dielectric multilayer mirrors, with the high absorptivity on the long wavelength side of the infrared (1000~2000 nm), which is characteristic of hot-wire absorption filters, the entire visible light region can be transmitted and infrared light can be efficiently blocked.
• It can also be used as a powerful infrared cut filter for CCD cameras.
• This filter prevents infrared light from appearing in the image.
• It can also be used in biomedical observation microscopes where you do not want the temperature of the specimen to change due to illumination.
• * If there is light incident at an angle from an angle to the filter, the transmittance will decrease on the longer wavelength side of the visible range.
• Placing the filter near a light source such as a lamp can cause sudden temperature changes due to infrared absorption, which can damage the filter.
• * There is no visible anti-reflection coat on the back of the cold filter.
• * For this reason, absorption by the hot-wire absorption filter and backside reflection (4%) can cause loss of 20% or less.