Blue LEDs, light emitting diodes, convert electrical energy into blue light. Blue LEDs can be purchased with different electrical specifications, in different sizes, and with different levels of brightness. Blue LEDs with different characteristics are used for different purposes.
Blue LED Color Variations
Blue LEDs come in different shades of blue, light, medium or dark. The shade of blue that a blue LED produces is directly related to the wavelength of light that the LED produces. Wavelength is the distance a specific color of light will travel over a fixed period of time.
Wavelength and Applications
For specific biological applications, the wavelength of the light that the blue LED generates must be known. That is because different life forms and organs respond differently to small variations in wavelength. Producers of blue LEDs often publish the wavelength of their blue LEDs. Wavelength is given in units of nanometers. One nanometer is one-billionth of a meter.
Because clinical evidence suggests blue light will eradicate many strains of bacteria, blue light emitting diodes are being used for the development of skin and dental care products. New dental care products on the market include toothbrush sanitizers. When the bacteria on the toothbrush is exposed to blue light, the bacteria is destroyed.
Because blue LEDs generate light with a wavelength in the range of 400 to 500 nanometers, they have potential to cause eye damage. The effect of blue LEDs on the eyes is a complex subject that involves many different factors. This makes it difficult to make a generalized statement about eye danger from blue LEDs. For this reason, staring at blue LEDs for any length of time should be avoided.
History and Technology
Blue LEDs first went into commercial production in the early 1990s. They preceded the commercial development of white LEDs. The design of white LEDs are based on the blue LEDs. One way to manufacture a white LED is to combine a blue, red and green LED together. Another way is to coat a blue LED with phosphorous.
Specifications and Pricing
Blue LEDs in general have a higher forward voltage, the voltage at which the LED will begin to emit light, than other colored LEDs, such as red and yellow. The forward current specification of a blue LED, the amount of electrical current that flows through it, does not differ dramatically from the forward current that flows in LEDs that emit different colors. For the most part, blue LEDs are priced in the same range of different colored LEDs.