RESUMEN
Quantum ghost image technique utilizing position or momentum correlations between entangled photons can realize nonlocal reconstruction of the image of an object. In this work, based on polarization entanglement, we experimentally demonstrate quantum ghost imaging of vector images by using a geometric phase object. We also provide a corresponding theoretical analysis. Additionally, we offer a geometrical optics path explanation of ghost imaging for vector fields. The proposed strategy offers new insights into the fundamental development of ghost imaging and also holds great promise for developing complex structured ghost imaging techniques. Our work expanding the principle of ghost imaging to spatially varying vector beams will lead to interesting developments of this field.
RESUMEN
It is a challenge for all-optical switching to simultaneous achieve ultralow power consumption, broad bandwidth and high extinction ratio. We experimentally demonstrate an ultralow-power all-optical switching by exploiting chiral interaction between light and optically active material in a Mach-Zehnder interferometer. We achieve switching extinction ratio of 20.0 ± 3.8 and 14.7 ± 2.8 dB with power cost of 66.1 ± 0.7 and 1.3 ± 0.1 fJ/bit, respectively. The bandwidth of our all-optical switching is about 4.2 GHz. Moreover, our all-optical switching has the potential to be operated at few-photon level. Our scheme paves the way towards ultralow-power and ultrafast all-optical information processing.
RESUMEN
Self-healing of an Airy beam during propagation is of fundamental interest and also promises important applications. Despite many studies of Airy beams in the quantum regime, it is unclear whether an Airy beam only including a single photon can heal after passing an obstacle because the photon may be blocked. Here we experimentally observe self-healing of a heralded single-photon Airy beam. Our observation implies that an Airy wave packet is robust against obstacle caused distortion and can restore even at the single-photon level.
RESUMEN
Here, we report a fiber-optic point-based sensor to measure temperature and weight based on correlated specklegrams induced by spatial multimode interference. The device is realized simply by splicing a multimode fiber (MMF) to a single-mode fiber (SMF) with a core offset. A series of experiments demonstrates the approximately linear relation between the correlation coefficient and variation. Furthermore, we show the potential applications of the refractive index sensing of our device by disconnecting the splicing point of MMF and SMF. A modification of the algorithm in order to improve the sensitivity of the sensor is also discussed at the end of the paper.
RESUMEN
A planar, all-optical fiber polarizer-based device based on a hybrid plasmonic microfiber knot resonator (HPMKR) is demonstrated in this Letter. A microfiber knot resonator (MKR) can be flexibly attached to the gold film, which forms the hybrid plasmonic mode with high propagation loss. Therefore, the device can be used not only as a broadband polarizer, but also as a high-quality resonator by tuning the geometry of the MKR. The polarizer has an extinction ratio of more than 15 dB ranging from 1200 to 1600 nm, and the Q-factor is more than 52,000 for one polarization state. For a chosen polarization, the resonator has an extinction ratio of nearly 15 dB, even though the diameter of the microfiber is more than 5 µm, which is unattainable for a normal MKR. By further optimizing and packaging, the device can be utilized as a weight sensor, with a sensitivity of 18.28 pm/g (51.2 pm/kPa) for the cavity resonant wavelength. Further, a vibration sensor on a HPMKR structure for detecting vibration from tens of hertz to several kilohertz is demonstrated.