Blue Laser Diode Definition & Technology
A blue semiconductor laser, or blue laser diode, is classified as any diode laser that emits laser light in the wavelength range of 370 nanometers to 488 nanometers. The longer wavelengths within this range actually appear to more violet to the human eye, but they are typically considered to be in the blue family. The most common wavelength is 405 nanometers. This wavelength is used more than any other in the blue range It is used in high volume consumer products applications such as blue-ray DVD. The economies of scale which have been created from the consumer applications makes this wavelength the most affordable. The blue laser output is a result of the semiconductor materials used to grow the laser diode chip. For these devices, the semiconductor material recipe is either based on gallium nitiride or indium gallium nitride. Blue diode lasers can also be created by frequency doubling longer wavelength IR lasers and DPSS lasers. To differentiate the frequency-doubled IR and DPSS lasers from a laser diode, a blue LD is often referred to as a "native blue" laser.
The violet/blue laser diode from Nichia (refer to data sheet attached) offers key features including optical output power of 1200 mW from a 9mm TO-can package. These are multi-transverse mode devices with a peak wavelength between 400 and 405nm. They are mounted with an internal zener diode. The typical threshold point for these lasers is between 150 milliamps and 400 milliamps. The forward power operating current to reach 1. 2 watts optical output is between 800 and 1400 milliamps. These devices are highly efficient sources with a slope efficiency up to 2.0 watts per amp. They have an operating voltage of less than 4.6 volts at their nominal operating power.