FAQs
Laser Diode Primer
A laser diode (or diode laser) is a semiconductor laser that produces coherent light when current is applied. Diode lasers are made of p-doped and n-doped semiconductor material with an active region in between. When current is applied, positively charged holes from the p-doped material combine with the negatively charged electrons from the n-doped material producing light in the form of photons. For more information, click here. (http://www.photonics.com/content/handbook/2006/lasers/82258.aspx)
A CW or Continuous Wave laser emits lights continuously, rather than in pulses. A QCW or Quasi Continuous Wave laser emits light in long pulses while a pulsed laser emits lights in nanosecond length pulses. Shortening the pulse reduces the thermal effects enabling higher powers. Although all wavelengths can be pulsed, not all packages can be pulsed.
A multimode laser contains multiple modes of light emission in two or more transverse or longitudinal modes while a single mode emits in a single cavity mode. Single mode lasers are characterized by small line widths (generally less than 5 microns) and low phase noise.
A broad area laser is another name for a multimode laser.