When you increase or decrease the wavelength of an LED (Light-Emitting Diode), it has several effects related to its spectral characteristics and color perception. Here are the main effects:
Increasing Wavelength: As you increase the wavelength of an LED, it shifts towards the red end of the visible spectrum. This results in a change in the perceived color from blue or greenish-blue to green, yellow, orange, or eventually red. The specific color change depends on the LED's initial wavelength and the range of wavelengths it can emit.
Decreasing Wavelength: Conversely, when you decrease the wavelength of an LED, it shifts towards the blue end of the visible spectrum. The perceived color changes from red or reddish-orange to orange, yellow, green, or eventually blue. Again, the exact color change depends on the LED's initial wavelength and its emission range.
International Commission on Illumination (CIE) Color Space: The CIE color space is a standardized system used to define and quantify colors. As you change the wavelength of an LED, its position in the CIE color space will also change. The CIE coordinates (x, y, or xyY) represent the color's chromaticity, which describes its hue and saturation. Increasing or decreasing the wavelength alters the chromaticity coordinates of the LED's emitted light in the CIE color space.
Luminous Intensity: The luminous intensity of an LED refers to the amount of light it emits in a particular direction. Generally, different wavelengths of light may have different luminous intensities. Increasing or decreasing the wavelength can affect the perceived brightness or intensity of the LED.
Energy and Photon Frequency: Wavelength and frequency are inversely related for light waves. Increasing the wavelength corresponds to decreasing the frequency and vice versa. As the wavelength changes, the energy carried by individual photons emitted by the LED also changes. Longer wavelengths correspond to lower-energy photons, while shorter wavelengths correspond to higher-energy photons.
It's important to note that the specific effects can vary depending on the LED's design, materials used, and the intended application. LED technology is diverse, and different LED types can have different spectral characteristics, color ranges, and behaviors.