This paper describes a new method to design a laser mirror with high reflectivity, wide reflection bandwidth and high laser- induced damage threshold. The mirror is constructed by three materials of HfO/TiO2/SiO2 based on electric field and temperature field distribution characteristics of all-dielectric laser high reflector. TiO/SiO2 stacks act as the high reflector (HR) and broaden the reflection bandwidth, while HfO2/SiO2 stacks are used for increasing the laser resistance. The HfO/ TiO/SiO2 laser mirror with 34 layers is fabricated by a novel remote plasma sputtering deposition. The damage threshold of zero damage probability for the new mirror is up to 39.6 J/cm^2 (1064 nm, 12 ns). The possible laser damage mechanism of the mirror is discussed.
The performance of broadband polarizing beam splitters(PBSs) is sensitive to the incident angle.By taking account of the spectrum of the laser source and using the needle optimization method,a large acceptance angle PBS for laser-based displays is designed.The average degrees of polarization in transmission and reflection can reach 0.989 and 0.980 for an acceptance angle of 13.6?in air using two materials,while better results of 0.993 and 0.989 for an acceptance angle of 14.8?in air are attained when three common materials are used.Both designs consist of 40 layers.
A two-dimensional (2D) distributed feedback (DFB) structure is fabricated on dye-doped sol-gel derived hybrid zirconia films by soft lithography. The Q-switched Nd:YAG laser ()~ = 532 nm) is used to pump these structures. The lasing emissions of the gain medium doped with Rhodamine 6G (Rh6G) in two perpendicular directions are shown, and the threshold pump energy is measured.
We report the deposition of Nb2O5 films on unheated BK-7 glass substrates using remote plasma sputtering system. The remote plasma geometry allows pseudo separation of plasma and target bias parameters, which offers complete deposition rate control. Using appropriate oxygen flow rates, high-density and low-loss Nb2O5 films are deposited with rates up to 0.49 nm/s. Lower deposition rates (~0.026 nm/s) can also be obtained by working at low target current and voltage and at low pressure. Nb2O5 films deposited at different rates have the refractive index of about 2.3 and the extinction coefficient as low as 6.9×10-5.