Tunable dual-channel filter based on the photonic crystal with air defects

Abstract

We propose a tuning filter containing two channels by inserting a defect layer (Air/Si/Air/Si/Air) into a one-dimensional photonic crystal of Si/SiO, which is on the symmetry of the defect. Two transmission peaks (1528.98 and 1564.74 nm) appear in the optical communication S-band and C-band, and the transmittance of these two channels is up to 100%. In addition, this design realizes multi-channel filtering to process large dynamic range or multiple independent signals in the near-infrared band by changing the structure. The tuning range will be enlarged, and the channels can be moved in this range through the easy control of air thickness and incident angle.

One-Dimensional Photonic Crystal with a Defect Layer Utilized as an Optical Filter in Narrow Linewidth LED-Based Sources

“…When compatible defects are introduced in the structure, defect modes appear within the PBG, and the 1DPhCs thus represent an electromagnetic counterpart of semiconductor crystals with many promising applications. These include optical filters [2][3][4][5][6], along with tunable ones [7][8][9][10][11][12], lasers [13], light-emitting diodes [14], active cavities [15], including optical field enhanced nonlinear absorption [16], optical sensors [17][18][19], fiber-optic sensors [20], humidity sensors [21], gas sensors [22][23][24][25], and photonic biosensors [26][27][28][29][30][31][32]. In addition, alternative designs to the 1DPhC-based optical filters are represented by the 2DPhC-based ones [33][34][35].…”

“…TPs represent waves at the interface between a metal and a 1DPhC, and this concept has a number of sensing applications [55][56][57][58][59]. Defect modes are related to all-dielectric 1DPhCs with defect layers or optical cavities [2][3][4][5][7][8][9][10][11][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. A defect layer introduced in the 1DPhC permits the existence of defect states that are characterized by strong confinement of light in the resonant cavity.…”

Distributed Bragg Reflectors Employed in Sensors and Filters Based on Cavity-Mode Spectral-Domain Resonances

“…Complex dielectric structures [ 1 ] such as one-dimensional photonic crystals (1DPhCs) or distributed Bragg reflectors (DBRs) have attracted enormous interest in research of various topics and applications, such as omnidirectional reflectors [ 2 ], polarization selectors [ 3 ], optical filters [ 4 , 5 , 6 , 7 ], and optical sensors, including Bloch surface wave (BSW) based sensors [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ], Tamm plasmon (TP)-based sensors [ 20 , 21 , 22 , 23 , 24 , 25 ], gas sensors [ 15 , 26 , 27 ], and photonic biosensors [ 28 , 29 , 30 , 31 , 32 , 33 ].…”

“…Most importantly, a direct free-space excitation of BSWs is not possible, contrary to TPs [ 20 ], as states of a 1DPhC within the band gap at the interface between a metal and the 1DPhC exist. This concept, which has been extensively studied and utilized [ 21 , 42 , 43 ], can also be extended to all-dielectric 1DPhC-based sensors employing defects or optical cavities [ 4 , 5 , 6 , 7 , 28 , 29 , 30 , 31 , 32 , 33 , 44 ], characterized by a strong confinement of light in the resonant cavity, which is manifested by very narrow resonances at the normal incidence of light both in transmission and reflection. These resonances exist within the wavelength range of the band gap and correspond to localized modes in the defect, for which its introduction in 1DPhC permits defect states.…”

Realisation of one‐dimensional (Si/SiO 2 ) N PC filter in visible light band

“…Liu et al [11] designed 1D PC structure to realise multiple channel optic filter theoretically and Srivastava and Ojha [12] designed a broadband optical reflector, Sahel et al [13] designed a quasi‐periodic cantor PC filter, which can be applied in optoelectronic devices. In 2017, our subject group Zhao et al [14] designed a dual‐channel tuning filter in the optical communication band, which can realise channel filtering to process large dynamic range or multiple independent signals in the near‐infrared band, based on theoretical simulation. However, the PC filters are also widely used in the visible light band.…”