TY - JOUR
T1 - High-Q factor photonic crystal cavities with cut air holes [Invited]
AU - Fang, Liang
AU - Gan, Xuetao
AU - Zhao, Jianlin
N1 - Publisher Copyright:
© 2020 Chinese Optics Letters.
PY - 2020/6/10
Y1 - 2020/6/10
N2 - Planar photonic crystal (PPC) cavities with high quality (Q) factors were currently designed by missing or moving air holes. Here, we propose that cutting air holes in PPC into semicircles could be considered as another strategy to realize and optimize cavities, presenting superiorities over cavities with missed or moved air holes in a higher Q factor and a smaller mode volume (Vmode). Examples are demonstrated: (1) in a PPC lattice, cutting two adjacent air holes promises a cavity mode with a Q exceeding 200, 500 and an ultrasmall mode volume Vmode < 0.329(λ/2 n)3; (2) in a PPC waveguide, cutting two air holes on opposite sides of the waveguide supports a cavity mode with a Q exceeding 104, 600 and a Vmode < 1.22(λ/2 n)3; (3) cutting the two air holes at the edges of an L3-type PPC cavity, the Q factor is optimized from 5500 to 124, 700, with an almost constant Vmode. The concept of cutting air holes to introduce defects in PPC also promises the design of PPC also waveguides with an engineered transmission loss and dispersion.
AB - Planar photonic crystal (PPC) cavities with high quality (Q) factors were currently designed by missing or moving air holes. Here, we propose that cutting air holes in PPC into semicircles could be considered as another strategy to realize and optimize cavities, presenting superiorities over cavities with missed or moved air holes in a higher Q factor and a smaller mode volume (Vmode). Examples are demonstrated: (1) in a PPC lattice, cutting two adjacent air holes promises a cavity mode with a Q exceeding 200, 500 and an ultrasmall mode volume Vmode < 0.329(λ/2 n)3; (2) in a PPC waveguide, cutting two air holes on opposite sides of the waveguide supports a cavity mode with a Q exceeding 104, 600 and a Vmode < 1.22(λ/2 n)3; (3) cutting the two air holes at the edges of an L3-type PPC cavity, the Q factor is optimized from 5500 to 124, 700, with an almost constant Vmode. The concept of cutting air holes to introduce defects in PPC also promises the design of PPC also waveguides with an engineered transmission loss and dispersion.
KW - Mode volume
KW - Photonic crystal cavity
KW - Quality factor
UR - http://www.scopus.com/inward/record.url?scp=85090558342&partnerID=8YFLogxK
U2 - 10.3788/COL202018.063603
DO - 10.3788/COL202018.063603
M3 - 文章
AN - SCOPUS:85090558342
SN - 1671-7694
VL - 18
JO - Chinese Optics Letters
JF - Chinese Optics Letters
IS - 6
M1 - 063603
ER -