A study of free standing diamond films for mm TWTs

We have studied the process of MPCVD diamond films for mm TWTs. Diamond films were found in a (111) preferential orientation, having an excellent crystalline structure with no SP 2 content. Free standing diamond film disks were fabricated for mm TWT windows, with a cutoff wavelength 225 nm, and a transmission ≥70%(λ≥2.5μm).