ABSTRACT
The fundamental output wavelength of a laser is limited by the linewidth of the atomic transition involved; this linewidth may be very narrow, giving essentially a fixed frequency output as in the case of Nd:YAG, or it may be relatively broad allowing some degree of tunability. Even for Ti:sapphire, however, the most widely tunable visible/near infrared laser gain medium, this tuning range is limited to ∼700-1100 nm and for most other laser sources it is significantly less.
