Diode lasers are becoming quite popular due to their compact size and relatively affordable pricing. A specialized semiconductor that produces monochromatic light when stimulated electrically is common to all diode lasers. A simple laser pointer is an example of a diode laser. Diode lasers can be used in both contact and non-contact mode and can function with continuous wave or gated pulse modes. They are not capable of free running pulsed mode. Diode lasers are invisible near infrared wavelengths and current machines range from 805–1064 nm. One exception is the Diagnodent caries diagnostic laser which uses a visible red wavelength of 655 nm.
Diode lasers are soft tissue only. The chromophores are pigments such as hemoglobin and melanin, similar to the Nd:YAG absorption spectrum. However, most surgical procedures with diodes are not as a result of laser photons interacting with tissue. Diode laser fibers are "initiated" by burning articulating paper on the tip. This initiation causes the light energy to be absorbed by the burnt material on the tip, effectively making it a hot piece of quartz. The laser energy cuts indirectly by heating up the fiber optic tip. Diode lasers do not have enough peak power to efficiently cut tissue on their own without initiation. If one defines "laser dentistry" as light interacting with tissue, then diode procedures are not laser dentistry ones.
They are quite effective for a host of intraoral soft tissue procedures such as gingivectomy, biopsy, impression troughing, and frenectomy. Diode lasers also exhibit bactericidal capabilities and can be used for adjunctive periodontal procedures. They also are used for laser assisted tooth whitening. Diode lasers have excellent photobiomodulation properties as well.