Optical fabrication and characterisation of SU-8 disk photonic waveguide heterostructure cavities

Abstract

In order to demonstrate cavity quantum electrodynamics using photonic crystal (PhC) cavities fabricated around self-assembled quantum dots (QDs), reliable spectral and spatial overlap between the cavity mode and the quantum dot is required. We present a method for using photoresist to optically fabricate heterostructure cavities in a PhC waveguide with a combined photolithography and micro-photoluminescence spectroscopy system. The system can identify single QDs with a spatial precision of ±25 nm, and we confirm the creation of high quality factor cavity modes deterministically placed with the same spatial precision. This method offers a promising route towards bright, on-chip single photon sources for quantum information applications.

III–V compounds as single photon emitters

“…To fabricate [47]. (e) and (f) illustrated a mode-gap cavity depicted in [86]. an SPE deterministically one needs to place a source spatially and spectrally at the antinode of a cavity mode.…”

“…One promising class of photonic crystal cavity design is the modulated mode-gap cavity [99]. One way of achieving such a cavity is to deposit a low refractive index material on top of a photonic crystal waveguide as shown in Fig 4e, f. The small photonic mode volume guarantees high Q cavities using an optical system, and thus greatly increases the probability of successful coupling between a QD and a cavity mode [86]. The lithography steps are straightforward, with a spatial precision of ±25 nm making the techniqure promising for scalable on-chip SPE systems [99].…”

“…Chen et al built a broadband optical antenna with a photon pair efficiency of 0.372 ± 0.002 and a fidelity of 0.9 [89] . Wang et al generated entangled photon pairs with a fidelity of 0.9, pair genera- g (2) (0) tion rate of 0.59 ± 0.01, of 0.014 ± 0.001 and simultaneously with photon indistinguishability of 0.90 ± 0.01 [85] . Liu et al even improved this photon count rate to >10 MHz [90] , realizing an unprecedented brightness of photon-pair generation as high as 0.65 (single-photon efficiency of 0.85).…”

Design of a microfluidic chip consisting of micropillars and its use for the enrichment of nasopharyngeal cancer cells

“…The SU-8 mould was prepared via a photolithographic process (16,17), while the PDMS array and cover slips were prepared by PDMS demoulding technology. The typical final step in preparing a closed chip for microfluidic experiments was accomplished using the bonding process (18,19). The chip was composed of an inlet, reaction chamber and an outlet; the reaction chamber was designed with an array of circular bypass columns in a staggered arrangement.…”