Effect of Photonic Cavity Interactions on Femtosecond Multiphoton Optical Nonlinear Absorptions from Bi₂O₃-Based One-Dimensional Photonic Crystal

Abstract

The photonic cavity-mediated precise control of femtosecond optical nonlinearity of several orders of magnitude enhancement is demonstrated in a novel nonlinear one-dimensional (1D) photonic crystal. The demonstrated photonic structure contains a highly nonlinear metal oxide, Bi 2 O 3 as a central defect layer within two SiO 2 /TiO 2 distributed Bragg reflectors. The nonlinear optical interactions of the electronic states of Bi 2 O 3 with the cavity mode and adjacent photonic minibands are closely monitored by femtosecond Gaussian laser beam propagation over a wide-range of spectral wavelengths, 350−1600 nm. Abnormal cross-over from positive (reverse saturation) nonlinear absorption (RSA, β = (+)12 × 10 −10 m W −1 ) to negative (saturation) nonlinear absorption (SA, β = (−) 11× 10 −10 m W −1 ) is witnessed when the confined optical fields are strongly coupled to the excitation laser and mid-band gap energies of Bi 2 O 3 , during effective cavity length tuning. The femtosecond laser pulse propagation at different wavelengths effectively probed the multiphoton-induced optical nonlinearities, which are distinctly different from lowand high-energy minibands compared to the cavity resonance and are manifold-enhanced relative to pristine Bi 2 O 3 . The photonic mode density-dependent pronounced two-/multiphoton absorptions are systematically analyzed with experiments and simulations. The novel photonic architecture can be utilized in optical switches, optical limiters, and ultrafast photonic device applications.

Ultrafast Dynamics and Strong Two-Photon Absorption Properties of Nonplanar β-Functionalized “Push–Pull” Copper Corroles with a Mixed Substituent Pattern

“…Figure depicts the CA Z-scan traces, and the results show a distinct valley–peak configuration which is the signature of a self-focusing-type positive nonlinear refractive index originating from the Kerr electronic response. The CA Z-scan data (Figure ) exhibits slight asymmetry due to the minor involvement of nonlinear absorption, which can be well described by incorporating the nonlinear absorption phase shift (Δψ) with the nonlinear refraction phase shift (ΔΦ) as follows T normalC normalA ( z ) = 1 − 4 ( z z r ) normalΔ normalΦ ( ( z z r ) 2 + 1 ) ( ( z z r ) 2 + 9 ) + 2 ( ( z z r ) 2 + 3 ) normalΔ ψ ( ( z z r ) 2 + 1 ) ( ( z z r…”

“…The CA Z-scan data (Figure 7) exhibits slight asymmetry due to the minor involvement of nonlinear absorption, which can be well described by incorporating the nonlinear absorption phase shift (Δψ) with the nonlinear refraction phase shift (ΔΦ) as follows. 98 (3)…”

Enhanced Femtosecond Nonlinearities and Multiphoton Absorptions in Discrete Bands of Porphyrins

“…Appropriate neutral density (ND) filters are used for laser intensity-dependent studies. All of the experiments have been performed much below the laser damage threshold limits. − …”

Tunable bidirectional perfect THz absorber realized by graphene-based one-dimensional photonic crystals

“…One-dimensional photonic crystal (1DPC) is the simplest photonic crystal structure and is easy to manufacture, which can be used to design absorbers [20][21][22][23], sensors [24][25][26] and so on [27][28][29]. In this paper, we make full use of the local properties of photonic crystals and the excellent optical properties of graphene, and propose a structure based on 1DPC and graphene which can achieve tunable multichannel perfect absorption.…”