DESIGN OF OPTICAL DEVICES BASED ON HYBRID PERIODIC/FIBONACCI PHOTONIC CRYSTAL IN THE VISIBLE AND THE NEAR INFRARED DOMAINS

In this work, we exploit photonic crystal heterostructures formed by the combination of periodic and Fibonacci structures to design promising optical devices acting in the visible and the near infrared domains. An hybrid structure of the type Bragg mirror- (Fibonacci) S is proposed to enhance the high re∞ection band through the one dimensional photonic crystal in the near infrared. The use of the conflguration exhibits a large photonic band gap at any angle of incidence and for both polarizations. The proposed structure is a quarter wavelength omnidirectional mirror of 37 layers with a bandwidth larger than that of the periodic structure with an increasing ratio 3.7, and it covers all the optical telecommunication wavelengths 0.85, 1.3 and 1.55"m. Then a second structure of the type Bragg mirror-(Fibonacci) S -Bragg mirror with varied optical thicknesses permits to conflne strongly the light giving a rise to a microcavity through the visible range with strong mode localisation. Since difierent physical phenomena have their own relevant physical scales, we exploit the physical properties of the proposed structures in difierent wavelength domains to obtain difierent optical devices. The transmission spectra are determined by using a theoretical model based on the Transfer Matrix Method (TMM).