Fabrication of broadband antireflection coating based on ion beam sputtering deposition technique with time-power monitoring

With the development of optical systems for multi-wavelength and wide-angle range, there is a requirement of the antireflection coating with wide-spectrum and wide-incidence angle range. In this paper, the substrate is super-smooth ZF6 (rms less than 0.6 nm) glass and HfO₂ and SiO₂ are selected as high index and low index materials, respectively. The broadband antireflection coating is designed, for wavelength form 600 to 1200 nm and incidence angle of 0° to 30°. The influences of refractive index inhomogeneity, error of refractive index and error of layer physical thickness on its transmittance are analyzed. Ion beam sputtering deposition of time-power thickness monitoring is used to manufacture the antireflection coating and the each layer thickness systematic correction coefficients are obtained by numerical optimization method from transmittance spectra. The average transmittance of the manufactured broadband antireflection coating achieves above 99%.