Efficient Modulation of Photonic Bandgap and Defect Modes in All‐Dielectric Photonic Crystals by Energetic Ion Beams

Abstract

The photonic bandgap and localization in photonic crystals can be effectively modulated by energetic ion beams owing to the induced modification of the thickness and refractive indices of the materials. In this work, the modulation of photonic bandgap and defect modes in 1D all‐dielectric photonic crystals is investigated theoretically and experimentally by using carbon (C5+) ion irradiation. It is found that the photonic bandgap and defect mode have a remarkable hypsochromic shift under the C5+ ion irradiation. The degree of the blueshift mainly depends on the reduction of the material thickness that is nearly proportional to the fluences of C5+ ions. The blueshift of the band edges and defect modes shows a step‐like behavior from transparency to opacification (near‐zero transmittance or high reflectance) or a converse trend. The work paves a new way to tailor the photonic crystals toward the development of novel devices with tunable specific wavelengths and wavebands.

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

“…In addition, the collimated beam represents a substantial advantage compared to a converging beam generating a spot of sub-millimeter diameter on the surface of a 1DPhC [68], especially for a filter employing an open cavity between two DBRs [19]. From various designs of 1DPhCs that have been used for optical filters [2][3][4][5][6][7][8][9][10][11][12] working in the NIR [2,3,5,8,10], UV [4], and Vis [6,7,9,11,12] spectral regions, only a few have been realized [4][5][6][7][8][9]11]. Our spectral filter outperforms them in the linewidth.…”

“…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.…”

“…1DPhCs with cavity mode resonances represent an effective alternative to various applications, as experimentally confirmed [2][3][4][5][7][8][9][10][11][13][14][15][16][17][18][19][20][21][22][23][24]. One of them refers to narrowband transmission filters and their potential applications in narrow linewidth sources.…”

Tunable perfect optical absorption in truncated photonic crystals with lossy defects

“…In this section, 1D PC containing a lossy defect layer is considered, which is denoted by (AB) M D(BA) N as is shown in Figure 1, where A and B denote TiO 2 and SiO 2 with refractive indices of n A = 2.123 and n B = 1.431, respectively [29,30]. M and N represent periodic numbers of the optical barriers on both sides of defect layer D, respectively.…”