Diode diodes 0.25 to 0.3 V, and red or blue light-emitting diodes (LEDs) can have values of 1.4 V and 4.0 V respectively. At higher currents the forward voltage drop of the diode increases. A drop of 1 V to 1.5 V is typical at full rated current for power diodes. The "Shockley ideal diode equation" or the "diode law" (named after the bipolar junction transistor co-inventor William Bradford Shockley) gives the I–V characteristic of an ideal diode in either forward or reverse bias (or no bias). The following equation is called the "Shockley ideal diode equation" when "n", the ideality
Laser diode frequency doubling of near-IR VECSEL emitters to produce blue and green light. External-cavity diode lasers are tunable lasers which use mainly double heterostructures diodes of the AlGaAs type. The first external-cavity diode lasers used intracavity etalons and simple tuning Littrow gratings. Other designs include gratings in grazing-incidence configuration and multiple-prism grating configurations. Laser diodes have the same reliability and failure issues as light emitting diodes. In addition they are subject to "catastrophic optical damage" (COD) when operated at higher power. Many of the advances in reliability of diode lasers in the last 20 years remain proprietary to their developers. The