Mechanisms of Radiation Effects on Lasers

Correlations between active and passive parameters of solid state laser media (I)

“…The energetic result of coloration is a higher threshold value and at strong colourability a lower efficiency in laser operation. Highly energetic irradiation causes qualitatively the same effects; an exception is a steeper rise of the input-output curve for ruby [71].…”

“…A theoretical description has to take into consideration that even at room temperature bleaching processes are superimposed on coloration and that each medium has characteristic decay constants. Of the Nd media CaWO, has the lowest time constant a t room temperature and low pumping energy [71]. Apart from thermal effects also photoelectric and photochemical processes play some part in bleaching [69].…”

Radiation dose rate effects on the properties of a laser-induced breakdown spectroscopy system developed using a ceramics micro-laser for fiber-optic remote analysis

“…By the comparison of the transmission using LD (808 nm) and Nd:YAG laser output (1064 nm), it was confirmed that the optical loss in the IR wavelength region was predominantly induced in the Nd:YAG part of the composite. Deterioration of laser performances by gamma-ray irradiation using the Nd:YAG single-crystal including output energy and slope efficiency reduction has been reported [22,33], where the effects were ascribed to the optical loss such as scattering [22] or absorption by generated color centers [33] in the Nd:YAG crystal. Based on the previous work's results, it is assumed that the dominant reason for the observed pulse energy reduction is an optical loss in the Nd:YAG ceramics of the system.…”

“…Radiation effects on devices such as semiconductor and optical components have been studied to improve their radiation tolerance, life-span, and reliability in applications such as space or fusion reactors [19,20]. Since it has been reported that the optical properties of Nd:YAG single crystal and laser properties were deteriorated by gamma-ray irradiation through generating additional color center absorption [21,22], in-situ LIBS signal may also be influenced by changes in laser properties such as pulse energy. Study of radiation effects is also required for future applications of the developed system such as sample analysis of the retrieved fuel debris out of the reactor site, a handy survey of the contaminated field, and monitoring of decontamination process, as well as the remote fuel debris inspection.…”

Impact of ionizing radiation on the optical properties of YAG laser materials

“…Shielding can reduce exposure of the material to electrons and low-energy protons, but exposure to high energy radiation is more difficult to protect against. In particular, it is known that gammaradiation exposure produces both transient and permanent optical loss in a broad range of optical materials [1][2][3] . Nd-doped Yttrium Aluminum Garnet (Nd:YAG) is a commonly used laser crystal that operates at a wavelength of 1.06 microns.…”