The ultra-violet wavelength region of the electromagnetic spectrum (for our purposes covering a wavelength range of 150-400 nanometers) is of increasing importance as many optical applications require shorter wavelengths. This is particularly true in the field of micro-lithography, where the quest for finer detail resolution requires the use of a shorter wavelength of light. Another field which uses UV light is that of ophthalmology, where the use of short wavelength laser radiation is enabling a whole range of non-invasive eye surgery.
Common sources producing ultra-violet radiation are mercury vapor lamps, excimer lasers, nitrogen lasers, helium-cadmium lasers some of the argon laser lines and the 3rd 4th and 5th harmonics of Nd: YAG and Nd: YLF. Ultra-violet light is also present in many broadband sources including the radiation we receive from the sun.
When looking at such short wavelengths, great care must be taken to prevent the occurrence of small defects in the optical components or their coatings. Also, coating layers are very thin requiring a high degree of precision and control in their deposition. Many common optical glasses cease to transmit at these wavelengths so it is essential to use a material such as UV grade Fused Silica, Calcium Fluoride or Magnesium Fluoride as component materials for transmissive optics. The fluoride materials are soft and hygroscopic which necessitates special handling and knowledge of the material shaping and polishing characteristics.
For a great deal of reliability in the design, manufacturing, and coating of ultra-violet optics, contact Lambda.
Lambda has a great deal of experience in the design, manufacture, and coating of ultra-violet optics.