Highly tolerant a-Si distributed Bragg reflector fabricated by oblique angle deposition

We demonstrate a highly tolerant and highly reflective broadband a-Si distributed Bragg reflector fabricated by oblique angle deposition. By tuning the refractive index of an a-Si film, a high index contrast material system was achieved. The highly tolerant and broadband reflective characteristics of the a-Si distributed Bragg reflector were investigated by calculation and fabrication. A broad stop band (Delta lambda/lambda = 33.7%, R>99%) with only a five-pair a-Si distributed Bragg reflector was achieved experimentally. The size-, feature- and substrate-independent method for highly reflective Bragg reflectors was realized by simple oblique angle evaporation. (C) 2011 Optical Society of America