Diamond films for laser hardening

Diamond has many unique physical properties useful as thin-film coatings for laser optics. The calculated value of the laser-induced stress resistance parameter of diamond is orders of magnitude higher than any other material and, therefore, diamond films should have a higher laser damage threshold. This is confirmed by laser damage experiments carried out on free-standing polycrystalline diamond films. Materials susceptible to laser damage can be protected by diamond thin-film coatings to enhance the damage threshold. This is demonstrated in the case of diamond coated silicon substrate.