Slow Light amplification in a non-inverted gain medium

Light transmission through and its complete stoppage in an ultra slow wave optical medium

Light Wave transmission -- its compression, amplification, and the optical energy storage -- in an Ultra Slow Wave Medium (USWM) is studied analytically. Our phenomenological treatment is based entirely on the continuity equation for the optical energy flux, and the well known distribution-product property of Dirac delta-function. The results so obtained provide a clear understanding of some recent experiments on light transmission and its complete stoppage in an USWM. Keywords : Ultra slow light, stopped light, slow wave medium, EIT.

Microwave Amplification in a PT -symmetric-like Cavity Magnomechanical System

We propose a scheme that can generate tunable magnomechanically induced amplification in a double-cavity parity-time-(PT -) symmetric-like magnomechanical system under a strong control and weak probe field. The system consists of a ferromagnetic-material yttrium iron garnet (YIG) sphere placed in a passive microwave cavity which is connected with another active cavity. We reveal that ideally induced amplification of the microwave probe signal may reach the maximum value 1000000 when cavity-cavity, cavity-magnon and magnomechanical coupling strengths are nonzero simultaneously. The phenomenon m…

用于布洛赫矢量放大的非线性与非CP门

Nonlinear and non-CP gates for Bloch vector amplification

本文研究从布洛赫球中心制备量子比特态的互补方案，提出基于线性和非线性马尔可夫PTP信道的布洛赫矢量放大方法，克服了线性CPTP信道的临界减速问题，并可用于实验演示非CP动力学。

Electromagnetically induced transparency and slow light in two-mode optomechanics

We theoretically demonstrate the mechanically mediated electromagnetically induced transparency in a two-mode cavity optomechanical system, where two cavity modes are coupled to a common mechanical resonator. When the two cavity modes are driven on their respective red sidebands by two pump beams, a transparency window appears in the probe transmission spectrum due to destructive interference. Under this situation the transmitted probe beam can be delayed as much as 4 us, which can be easily controlled by the power of the pump beams. In addition, we also investigate the amplification of the tr…

连续量子光力学中通过布里渊散射实现慢光

Slow Light through Brillouin Scattering in Continuum Quantum Optomechanics

提出利用双泵浦受激布里渊散射在纳米光纤中实现无增益无损耗、宽带宽的单光子级慢光，并分析热声子噪声可忽略的条件。

Parametric amplification of light in a cavity with a moving dielectric membrane: Landau-Zener problem for the Maxwell field

We perform a theoretical investigation into the classical and quantum dynamics of an optical field in a cavity containing a moving membrane ("membrane-in-the-middle" set-up). Our approach is based on the Maxwell wave equation, and complements previous studies based on an effective Hamiltonian. The analysis shows that for slowly moving and weakly reflective membranes the dynamics can be approximated by unitary, first-order-in-time evolution given by an effective Schrödinger-like equation with a Hamiltonian that does not depend on the membrane speed. This approximate theory is the one typically …

Phase-controlled pathway interferences and switchable fast-slow light in a cavity-magnon polariton system

We study the phase controlled transmission properties in a compound system consisting of a 3D copper cavity and an yttrium iron garnet (YIG) sphere. By tuning the relative phase of the magnon pumping and cavity probe tones, constructive and destructive interferences occur periodically, which strongly modify both the cavity field transmission spectra and the group delay of light. Moreover, the tunable amplitude ratio between pump-probe tones allows us to further improve the signal absorption or amplification, accompanied by either significantly enhanced optical advance or delay. Both the phase …

在相干预置的三线结构中慢光光学矢量涡流的传播

Propagation of optical vector vortices of slow light in a coherently prepared tripod configuration

研究慢光光学矢量涡流在四能级三线原子系统中的传播，揭示涡流OAM与介质相互作用及动态各向异性对慢光涡流强度和偏振的影响。

$\mathcal{PT}$-对称腔体磁机械学与增益辅助透明与放大

$\mathcal{PT}$-symmetric cavity magnomechanics with gain-assisted transparency and amplification

研究PT对称腔体磁机械系统，通过非厄米特耦合实现增益辅助透明与放大，展示可调制的量子信号处理与传感应用。

Optomechanically-Induced Transparency in partiy-time-symmetric microresonators

Optomechanically-induced transparency (OMIT) and the associated slowing of light provide the basis for storing photons in nanoscale devices. Here we study OMIT in parity-time (PT)-symmetric microresonators with a tunable gain-to-loss ratio. This system features a reversed, non-amplifying transparency, i.e., an inverted-OMIT. When the gain-to-loss ratio is varied, the system exhibits a transition from a PT-symmetric phase to a broken-PT-symmetric phase. This PT-phase transition results in the reversal of the pump and gain dependence of the transmission rates. Moreover, we show that by tuning th…

Exact formulas of the end-to-end Green's functions in non-Hermitian systems

Green's function in non-Hermitian systems has recently been revealed to be capable of directional amplification in some cases. The exact formulas for end-to-end Green's functions are significantly important for studies of both non-Hermitian systems and their applications. In this work, based on the Widom's formula, we derive exact formulas for the end-to-end Green's functions of single-band systems which depend on the roots of a simple algebraic equation. These exact formulas allow direct and accurate comparisons between theoretical results and experimentally measured quantities. In addition, …