Selective photothermolysis to target sebaceous glands: theoretical estimation of parameters and preliminary results using a free electron laser.

Background And Objectives: The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH(2) bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH(2) vibrational absorption wavelength band.

Femtosecond pulse damage thresholds of dielectric coatings in vacuum.

The dielectric breakdown behavior of dielectric coatings in studied for different ambient gas pressures with femtosecond laser pulses. At 10(-7) Torr, the multiple femtosecond pulse damage threshold, Fm, is about 10% of the single pulse damage fluence F(1) for hafnia and silica films compared to about 65% and 50%, respectively, at 630 Torr. In contrast, the single-pulse damage threshold is pressure independent.

Selective photothermolysis of lipid-rich tissues: a free electron laser study.

Background And Objectives: In theory, infrared vibrational bands could be used for selective photothermolysis of lipid-rich tissues such as fat, sebaceous glands, or atherosclerotic plaques.

Study Design/materials And Methods: Absorption spectra of human fat were measured, identifying promising bands near 1,210 and 1,720 nm. Photothermal excitation of porcine fat and dermis were measured with a 3.