Charles B. Zarowin

New ‘‘diamondlike carbon’’ film deposition process using plasma assisted chemical vapor transport

We have deposited ‘‘diamondlike carbon’’ films on various substrates using a new plasma assisted chemical vapor transport process in a high rf power density presssure ratio gas discharge. The films reported here exhibit the following properties: (1) high transparency for wavelengths greater than 300 nm; (2) an index of refraction of ∼2 at 850 nm; (3) a hardness between that of quartz and sapphire, increasing with ion energy bombarding the deposition surface; (4) strong adhesion to KBr, sapphire, and Si substrates; (5) high dielectric strength; (6) inertness to highly reactive chemicals.

Rapid optical figuring of aspherical surfaces with plasma-assisted chemical etching

Programmed motion of a tool which removes material by plasma assisted chemical etching (PACE) gives controlled, deterministic figuring. The process has been automated to correct arbitrary figure errors on aspheric surfaces directly from the measured surface data. A system is now operating for figuring aspheric surfaces up to 0.5 m diameter. PACE can greatly reduce the time and cost of figuring large optics by its rapid convergence to the final figure requiring only two to three measurement/figuring cycles to reach 1/50 wave surfaces. PACE intrinsically smooths high frequency roughness with material removal leaving a surface free of subsurface damage