The article describes a hardware-software complex for measurement of characteristics of electric and optical noise of light emitting diodes (LED) in a range of frequencies from 1 kHz to 40 kHz by a method of discrete samples. Electric noise of several types of heterojunction LEDs is investigated: red with quantum holes (QH) on the basis of AlInGaP/GaAs, green and blue without QH on the basis of AlInGaN/SiC. Spectra of all investigated LEDs in a range of frequencies from 1 kHz to 10 kHz look like 1/f γ;, meanwhile at red LEDs value of factor is much lower than 1, and at green and blue - is close to 1, and the noise correlation time of red LEDs several times exceeds correlation time of blue and green LEDs. It is demonstrated that the resulted functions of noise distribution at all LEDs types are close to a Gaussian with approximately identical dispersion.
Ilya V. Frolov
Ulyanovsk Branch of Kotel’nikov Institute of Radioengineering and Electronics of Rus-sian Academy of Sciences, Ulyanovsk, Russia