All-optical analogs of electromagnetically induced absorption (EIA) and electromagnetically induced transparency (EIT) are important for light storage, sensing, and optical communication. Here, we report results of a computational study focusing on the EIA and EIT characteristics of triple-microcavity hosting one-dimensional photonic crystals (PHCs). In contrast to previous experimental investigation of dual PHC cavities, realization EIA and EIT in the triple-cavity PHC is not restricted to reflection and transmission, respectively. In addition, the dispersive response of the triple-cavity is also distinct since EIA in the triple-cavity may lead to the generation of both sub- and superluminal light pulses. Furthermore, the dispersion of the system at either output may be reversed by altering the distribution of the coupled light among the three cavities. Finally, we discuss the experimental implementation of these features based on a single monolithic PHC and show tuning of the EIA and EIT phenomenon over a broad spectral range by using strain-tunable polymer-based PHC microcavities. Among others, these findings are advantageous for realizing ultra-narrow bandwidth optical filters, all-optical switching, temporal control of cavity quantum electrodynamics effects, and on-chip dispersion control.
All-optical analogs of electromagnetically induced absorption (EIA) and electromagnetically induced transparency (EIT) are important for light storage, sensing, and optical communication. Here, we report results of a computational study focusing on the EIA and EIT characteristics of triple-microcavity hosting one-dimensional photonic crystals (PHCs). In contrast to previous experimental investigation of dual PHC cavities, realization EIA and EIT in the triple-cavity PHC is not restricted to reflection and transmission, respectively. In addition, the dispersive response of the triple-cavity is also distinct since EIA in the triple-cavity may lead to the generation of both sub- and superluminal light pulses. Furthermore, the dispersion of the system at either output may be reversed by altering the distribution of the coupled light among the three cavities. Finally, we discuss the experimental implementation of these features based on a single monolithic PHC and show tuning of the EIA and EIT phenomenon over a broad spectral range by using strain-tunable polymer-based PHC microcavities. Among others, these findings are advantageous for realizing ultra-narrow bandwidth optical filters, all-optical switching, temporal control of cavity quantum electrodynamics effects, and on-chip dispersion control.
We report the first experimental realization of all-optical electromagnetically induced transparency (EIT) via a pair of coherently interacting SiO2 microcavities in a one-dimensional SiO2/Si3N4 photonic crystal consisting of a distributed Bragg reflector (DBR). The electromagnetic interactions between the coupled microcavities (CMCs), which possess distinct Q-factors, are controlled by varying the number of embedded SiO2/Si3N4 bilayers in the coupling DBR. In case of weak microcavity interactions, the reflectivity spectrum reveals an all-optical EIT resonance which splits into an Autler-Townes-like resonance under condition of strong microcavity coupling. Our results open up the way for implementing optical analogs of quantum coherence in much simpler one-dimensional structures. We also discuss potential applications of CMCs.
Abstract Electromagnetically induced transparency (EIT) is a quantum interference effect arising from different transition pathways of optical fields. Within the transparency window, both absorption and dispersion properties strongly change, which results in extensive applications such as slow light and optical storage. Due to the ultrahigh quality factors, massive production on a chip and convenient all‐optical control, optical microcavities provide an ideal platform for realizing EIT. Here we review the principle and recent development of EIT in optical microcavities. We focus on the following three situations. First, for a coupled‐cavity system, all‐optical EIT appears when the optical modes in different cavities couple to each other. Second, in a single microcavity, all‐optical EIT is created when interference happens between two optical modes. Moreover, the mechanical oscillation of the microcavity leads to optomechanically induced transparency. Then the applications of EIT effect in microcavity systems are discussed, including light delay and storage, sensing, and field enhancement. A summary is then given in the final part of the paper.
Recently Qu and Agarwal [Phys. Rev. A 22, 031802 (2013)] found a three-pathway electromagnetically induced absorption (TEIA) phenomenon within a mechanically coupled two-cavity system, where there exist a sharp EIA dip in the broad electromagnetically induced transparency peak in the transmission spectrum. In this work, we study the response of a probe light in a pair of directly coupled microcavities with one mechanical mode. We find that in addition to the sharp TEIA dip within a broad EIT window as found by Qu and Agarwal, three-pathway electromagnetically induced transparency (TEIT) within the broad EIT window could also exist under certain conditions. We give explicit physical explanations and detailed calculations. Our results provide a method for controlling transition between TEIA and TEIT in coupled optomechanical systems, and reveal the multiple pathways interference is versatile for controlling light.
Quantum coherence in atomic systems has led to fascinating outcomes, such as laser cooling and trapping, Bose-Einstein condensates, and electromagnetically-induced-transparency (EIT). In EIT, the sharp cancellation of medium absorption has led to phenomena such as lasing without inversion, freezing light, and dynamic storage of light in a solid-state system. Similar to atomic systems, EIT-like effects can be observed through classical and optical means. Here we report the first experimental deterministic tuning of all-optical analogue to EIT in coherently-coupled standing-wave photonic crystal cavities. Our observations include transparency-resonance lifetimes more than three times the single loaded cavity, Fano-type lineshapes, and stepwise control of the coherent cavity-cavity interference. Our system, with wavelength-scale localization and coupled to a single waveguide, is analyzed well through the coupled-mode formalism which examines the delay in both transparency- and Fano-like lineshapes. Our observations support applications towards all-optical trapping, stopping and time-reversal of light in a solid-state scalable implementation.
The optical analogs of electromagnetically induced transparency (EIT) have attracted vast attention recently. The generation and manipulation of EIT in microcavities have sparked research in both fundamental physics and photonic applications, including light storage, slow light propagation, and optical communication. In this Letter, the generation and tuning of an all-optically controlled mode-coupling induced transparency (MCIT) are proposed, experimentally demonstrated, and theoretically analyzed. The MCIT effect originated from the intermodal coupling between the plethora of modes generated in our fabricated optical microcavity, and the tuning of the transparency mode utilized the cavity's thermal bistability nature. Furthermore, based on our method, a novel, to the best of our knowledge, controlling of the mode shifting efficiency is also achieved with an increase up to two times and more. The proposed scheme paves a unique, simple, and efficient way to manipulate the induced transparency mode, which can be useful for applications like cavity lasing and thermal sensing.
Controlling the optical response of a medium through suitably tuned coherent electromagnetic fields is highly relevant in a number of potential applications, from all-optical modulators to optical storage devices. In particular, electromagnetically induced transparency (EIT) is an established phenomenon in which destructive quantum interference creates a transparency window over a narrow spectral range around an absorption line, which, in turn, allows to slow and ultimately stop light due to the anomalous refractive index dispersion. Here we report on the observation of a new form of both induced transparency and amplification of a weak probe beam in a strongly driven silicon photonic crystal resonator at room temperature. The effect is based on the oscillating temperature field induced in a nonlinear optical cavity, and it reproduces many of the key features of EIT while being independent of either atomic or mechanical resonances. Such thermo-optically induced transparency will allow a versatile implementation of EIT-analogs in an integrated photonic platform, at almost arbitrary wavelength of interest, room temperature and in a practical, low cost, and scalable system.