A STUDY ON THE ROLE OF DYE LASERS

Dye Lasers Definition: lasers based on liquid or solid dyes as gain media A dye laser is a laser based on a dye (typically in a liquid solution) as the gain medium. Most laser dyes are based on organic molecules used in liquid form as solutions, although solid laser dyes and vapor dyes exist. A wide range of emission wavelengths from the ultraviolet to the near-infrared region can be addressed with different laser dyes. Typical characteristics of laser dyes as gain media are: They exhibit a broad gain bandwidth, which allows for broad wavelength tunability and also ultra short pulse generation with passive mode locking. Upper-state lifetimes are typically a couple of nanoseconds, i.e., similar to those of semiconductor lasers, but orders of magnitude shorter than those of doped-insulator lasers. This means that dyes are not suitable for Q switching with continuous or long-pulse pumping. However, intense dye laser pulses can be obtained with pulsed pumping, using a Q-switched pump laser or a flash lamp. The gain per unit length can be fairly high (order of 103 cm−1), particularly for pulsed pumping. The power conversion efficiency is typically between 10% and 30% for laser pumping, and possibly lower for flash lamp pumping.

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