Ultraviolet laser contamination of quartz optics

Area of Science:

• Optics and Photonics
• Materials Science
• Laser Technology

Background:

• Quartz polarizers are critical components in continuous-wave (cw) ultraviolet (UV) laser systems.
• Degradation of these optical components can lead to system failure and reduced performance.
• The specific cause of degradation in UV laser optics using quartz polarizers was not fully understood.

Purpose of the Study:

• To identify the root cause of degradation in quartz polarizers used with a cw UV laser.
• To investigate the role of adhesives in the deterioration of UV laser optics.
• To propose alternative solutions for mounting optical components in UV laser systems.

Main Methods:

• Laboratory experiments were performed on damaged quartz polarizers.
• UV transmission spectra were analyzed for degraded optical samples.
• X-ray photoelectron spectroscopy (XPS) was utilized to examine the surface composition of the damaged optics.
• Laser-induced photolysis experiments were conducted on adhesive materials.

Main Results:

• Analysis indicated that UV photolysis of adhesive residue is the most probable cause of polarizer degradation.
• Spectroscopic measurements revealed changes consistent with UV-induced chemical alteration of the adhesive.
• Laser-induced photolysis confirmed the susceptibility of the adhesive to UV radiation.

Conclusions:

• Organic adhesives are a significant risk factor for the degradation of quartz polarizers in UV laser applications.
• It is recommended to avoid the use of organic adhesives in UV laser optics.
• An adhesive-free method for securing quartz beam splitters has been developed and successfully implemented.