分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Mid-wave infrared (MWIR) cameras for large number pixels are extremely expensive compared with their counterparts in visible light, thus, super-resolution imaging (SRI) for MWIR by increasing imaging pixels has always been a research hotspot in recent years. Over the last decade, with the extensively investigation of the compressed sensing (CS) method, focal plane array (FPA) based compressive imaging in MWIR developed rapidly for SRI. This paper presents a long-distance super-resolution FPA compressive imaging in MWIR with improved calibration method and imaging effect. By the use of CS, we measure and calculate the calibration matrix of optical system efficiently and precisely, which improves the imaging contrast and signal-to-noise ratio(SNR) compared with previous work. We also achieved the 4x4 times super-resolution reconstruction of the long-distance objects which reaches the limit of the system design in our experiment.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We investigate the single-photon blockade (1PB) in the quasichiral regime of atom-photon interaction that mediates via dissipative environment, where the effective atom-photon interaction is asymmetrical but achiral. The synthetic magnetic current in the closed-loop coupling breaks down the reciprocity of atom-photon interaction, resulting in an asymmetrical and even completely unidirectional effective coupling between two selected quantum states. As an example, we couple the single-atom cavity-QED (cQED) system to a strongly dissipative auxiliary cavity. We find that in the quasichiral regime, the unconventional photon blockade (UPB) always incorporates with the conventional photon blockade (CPB) in the condition of maximum chirality. Furthermore, we show that 1PB in the quasichiral regime combines the advantages of UPB and CPB, demonstrating the perfect single-photon purity, higher efficiency, smooth time dynamics as well as lower requirement of modes coupling to achieve UPB. Our work paves the way for 1PB towards practical applications and reveals the intriguing quantum-optics phenomena in the quasichiral light-matter interaction.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Optical orbital angular momentum (OAM), as an important degree of freedom of light, has been attracted extensive attention, due to its intrinsic feature of natural discrete infinite dimension. Manipulation of OAM spectra is crucial for many impressive applications from classical to quantum realms, in particular, nonlinear manipulation of OAM spectra. Here we realized the nonlinear manipulation of OAM spectra by using the simultaneous second- and third-harmonic generation in a single nonlinear crystal of quasi-periodically poled potassium titanyl phosphate, for fundamental waves with a variety of OAM spectra, especially for customized OAM spectra of the second and third harmonics. The experimental results confirmed the theoretical predictions. Our approach not only provides a novel way to manipulate OAM spectra at new shorter wavelengths that are hard to be directly generated, but also may find new applications towards multiplexing in classical optics and high-dimensional information processing in quantum optics.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Coherently driven semiconductor quantum dots are one of the most promising platforms for non-classical light sources and quantum logic gates which form the foundation of photonic quantum technologies. However, to date, coherent manipulation of quantum dots is limited mainly to their lowest orbital states. Ultrafast coherent control of high-orbital states is obstructed by the demand for tunable terahertz pulses. To break this constraint, we demonstrate an all-optical method to control high-orbital states of a hole via stimulated Auger process. The coherent nature of the Auger process is revealed by Rabi oscillation and Ramsey interference with a fidelity of 95.8%. Harnessing this coherence further enables the investigation of single-hole relaxation mechanism. A surprisingly long relaxation time (156(2) ps) is observed and explained by phonon bottleneck effect. Our work opens new possibilities for understanding the fundamental properties of high-orbital states in quantum emitters and developing new types of orbital-based quantum photonic devices.