We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency (EIT) effect. We demonstrate that the isolation between the waveguide and the cavities cannot be achieved instantly as soon as the two cavities are tuned into resonance, no matter the index tuning rate is ultrafast or slow. We also investigate the temporal evolution features of the intracavity energy when the pulse during time is prolonged. We find many periodical oscillations of the trapped energy in both cavities, and they are entirely complementary. Our analysis shows that the adiabatic wavelength conversion in both cavities and a phase difference π between them play critical roles in this phenomenon.
We analytically and numerically investigate a signal light storing mechanism based on the controllable electromagnetically induced transparency (EIT) effect. We demonstrate that the isolation between the waveguide and the cavities cannot be achieved instantly as soon as the two cavities are tuned into resonance, no matter the index tuning rate is ultrafast or slow. We also investigate the temporal evolution features of the intracavity energy when the pulse during time is prolonged. We find many periodical oscillations of the trapped energy in both cavities, and they are entirely complementary. Our analysis shows that the adiabatic wavelength conversion in both cavities and a phase difference π between them play critical roles in this phenomenon.
We propose an effective method to achieve extremely slow light by using both the mechanism of electromagnetically induced transparency (EIT) and the localization of a coupled cavity waveguide (CCW). Based on quantum mechanics theory and the dispersion relation of a CCW, we derive a group-velocity formula that reveals both the effects of the EIT and CCW. Results show that ultralow light velocity at the order of several meters per second or even static light, could be obtained feasibly. In comparison with the EIT mechanism in a background of vacuum, this proposed method is more effective and realistic to achieve extremely slow light. And it exhibits potential values in the field of light storage.
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.
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.
Optical interference and the related effects are key elements which could exhibit the properties of both classical and quantum optical systems. Usually, the interference between different optical paths may produce intriguing effects, such as the electromagnetically induced transparent (EIT) and so on. In this work, we study the interference effects in directly coupled whispering-gallery mode (WGM) micro-resonators, in which the emergence of EIT and electromagnetically induced absorption (EIA) could be observed. We find by tuning the coupling strength between the resonators, the modulation phase may control the appearance and disappearance of EIT (EIA). Furthermore, we prove the existence of fast and slow light, and propose a scheme for effective switching between them. This work provides a new strategy for obtaining slow light and quantum storage in the WGM micro-resonators.
By applying a traveling-wave coupling field,a standing-wave grating field,and a static magnetic field to a cold atomic ensemble,a dynamically controlled cavity consisting of two Bragg regions of high reflection and an electromagnetically induced transparency region with high transmission is realized.With modulating all the three fields in time,a weak probe pulse is sent into the coherently induced optical cavity to achieve several periodic oscillations and then it is retrieved after a short time.This physical phenomenon is accompanied with little energy loss and can be regarded as an efficient scheme for dynamic light storage.This paper simulates the dynamic light storage scheme,discusses numerically its advantages and presents the developing trend of the scheme.
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.