Spin-preserving chiral photonic crystal mirror

Abstract

Chirality refers to a geometric phenomenon in which objects are not superimposable on their mirror image. 1 Structures made of nano-scale chiral elements can display chiroptical effects, such as dichroism for left-and right-handed circularly polarized light, which makes them of high interest for applications ranging from quantum information processing and quantum optics 2,3 to circular dichroism spectroscopy and molecular recognition. 4 At the same time, strong chiroptical effects have been challenging to achieve even in synthetic optical media and chiroptical effects for light with normal incidence has been speculated to be prohibited in lossless, thin, quasi-twodimensional structures. 5-8 Here, we report on our experimental realization of a giant chiroptical effect in a thin monolithic photonic crystal mirror. Unlike conventional mirrors, our structure selectively reflects only one spin state of light, while preserving its handedness, with a near unity level of circular dichroism. The operational principle of the photonic-crystal mirror relies on Guided Mode Resonance (GMR) with 1 arXiv:1911.09227v1 [physics.optics] 21 Nov 2019 simultaneous excitation of leaky TE and TM Bloch modes in the photonic crystal slab.Such modes are not reliant on the suppression of their radiative losses through the long-range destructive interference and even small areas of the photonic-crystal exhibit robust circular dichroism. Despite its simplicity, the mirror strongly surpasses the performance of earlier reported structures and, contrary to a prevailed notion, demonstrates that near unity reflectivity contrast for the opposite helicities is achievable in a quasi-two-dimensional structure.

Chirality Transfer from Sub‐Nanometer Biochemical Molecules to Sub‐Micrometer Plasmonic Metastructures: Physiochemical Mechanisms, Biosensing, and Bioimaging Opportunities

“…Recent demonstrations show that near-unity CD signals can be realized in chiral folded metasurfaces in the infrared region and in chiral photonic crystal mirrors in the visible region, both fabricated by top-down techniques with high accuracy. [225,226] However, low-cost and large-scale synthesis methods for chiral nanomaterials are the basic prerequisites that can promote relevant practical applications. Alternatively, the bottom-up approaches discussed in this review can enable scalable and inexpensive synthesis, yet at the cost of limited design flexibility and fabrication fidelity, representing an overarching challenge for bottom-up approaches.…”

Circularly polarized luminescence from organic micro-/nano-structures

“…Chirality refers to the geometric property of an object that cannot overlap with its mirror image 15 , 16 . Chiral molecules usually exhibit unique photophysical properties, such as optical rotatory dispersion, circular dichroism (CD), and circularly polarized luminescence (CPL) 17 – 20 .…”

A physical interpretation of coupling chiral metaatoms

“…24,40,41 For example, two-dimensional planar metasurfaces are geometrically achiral in three dimensions, 42 but they can still produce non-zero CD signals. 43,44 This phenomenon, also termed 2D chirality, is reported to have no contribution to optical activities. [45][46][47] In addition, CPC and AT effects could be absent in chiral materials (e.g., an infinite slab of Pasteur medium), suggesting that they are not the fundamental mechanism for chirality.…”