Search results
Results from the WOW.Com Content Network
By selection of different semiconductor materials, single-color LEDs can be made that emit light in a narrow band of wavelengths from near-infrared through the visible spectrum and into the ultraviolet range. The required operating voltages of LEDs increase as the emitted wavelengths become shorter (higher energy, red to blue), because of their ...
The materials used for the LED have a direct band gap with energies corresponding to near-infrared, visible, or near-ultraviolet light. LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have enabled making devices with ever-shorter wavelengths, emitting light in a variety of colors.
An external yellow photographic filter is used (Wratten #12 or equivalent) to block the blue and violet wavelengths, which results in a false-color image by translating or remapping the captured spectrum (from green through infrared) to the visible spectrum: Infrared wavelengths are mapped to the red color, even though the infrared wavelengths ...
Infrared Color Photography Mahatma Gandhi. Infrared cut-off filters, sometimes called IR filters or heat-absorbing filters, are designed to reflect or block near-infrared wavelengths while passing visible light. They are often used in devices with bright incandescent light bulbs (such as slide and overhead projectors) to prevent unwanted heating.
Infrared heaters can be operated in vacuum or atmosphere. One classification of infrared heaters is by the wavelength bands of infrared emission. Short wave or near infrared for the range from 750 nm to 1.4 μm; these emitters are also named "bright" because still some visible light is emitted; Medium infrared for the range between 1.4 μm and ...
Remote controls and IrDA devices use infrared light-emitting diodes (LEDs) to emit infrared radiation which is focused by a plastic lens into a narrow beam. The beam is modulated, i.e. switched on and off, to encode the data. The receiver uses a silicon photodiode to convert the infrared radiation to an electric current. It responds only to the ...
Kodak High-Speed Infrared film, also known as Kodak HIE, was a popular black-and-white infrared photographic film from Kodak.The film was sensitive to the visible light spectrum (with decreased green sensitivity), infrared radiation up to 900nm in wavelength, and some ultraviolet radiation as well.
The laser diode chip is the small black chip at the front; a photodiode at the back is used to control output power. SEM (scanning electron microscope) image of a commercial laser diode with its case and window cut away. The anode connection on the right has been accidentally broken by the case cut process.