The combination of metallic structure and graphene has become a promising platform for electrically controlled plasmonic devices. However, the current designs mainly utilize graphene as an active medium, which only modulate the devices performance slightly and the applications in tunable magnetic response have not been explored. Here, we explore the applications of graphene in the control of magnetic resonance in nanoantennas. By optimizing the design and parameter of the nanoantennas, gold–graphene hybrid diabolo antennas turn out to be the best candidate to achieve tunable magnetic response in mid-infrared wavelength range. The magnetic resonance of gold–graphene hybrid diabolo antennas has been significantly tuned from 32.3 μm to 19.8 μm, which is beyond one order of magnitude higher than conventional diabolo nanoantennas with graphene as active materials below the antenna structure. The corresponding absorption modulation and magnetic field enhancement can be as high as 12% and 1460%, respectively.

Solution‐processed lead halide perovskites have shown good applicability in both solar cells and microlasers. Very recently, the nonlinear properties of perovskites have attracted considerable research attention. Second harmonic generation and two‐photon absorption have been successfully demonstrated. However, perovskite devices based on these nonlinear properties, such as micro‐ and nanolasers have thus far not been fabricated. Here we demonstrate two‐photon pumped microlasers from CH3NH3PbBr3 perovskite microwires. These CH3NH3PbBr3 perovskite microwires are synthesized through a one‐step solution precipitation method and dispersed on a glass substrate. Under optical excitation at 800 nm, two‐photon pumped lasing action with periodic peaks is successfully observed at around 546 nm. The obtained quality (Q) factors of the two‐photon pumped microlasers are around 682, and the corresponding thresholds are about 674 µJ cm‐2. Both the Q factors and thresholds are comparable to conventional whispering‐gallery modes in two‐dimensional polygon microplates. This work is the first demonstration of two‐photon pumped microlasers in CH3NH3PbBr3 perovskite microwires. We believe our finding will significantly expand the application of perovskites in low‐cost nonlinear optical devices, such as optical limiters, optical switches, and biomedical imaging devices.

Perovskite microdisk lasers have been intensively studied recently. But their lasing properties are usually fixed once the devices are synthesized. Here, for the first time, we demonstrated the switchable and tunable perovskite microdisk lasers by surrounding them with 5CB liquid crystals. With the increase of the environmental temperature from 24 °C to 34 °C, the lasing wavelength slightly changed from 552.91 nm to 552.11 nm at the beginning and suddenly shifted to around 552.54 nm at T = 32 °C, where the phase transition of liquid crystals occurs. Our numerical calculation shows that the wavelength shift is caused by the changes of the refractive index of liquid crystals. More than tuning of the wavelength, a more dramatic wavelength transition from ∼554 nm to 550 nm has also been observed. This sudden transition is mainly induced by the reduction of scattering rather than the change in the refractive index when the liquid crystals are changed from the nematic phase to the isotropic phase. We believe that our research can shed light on the applications of perovskite optoelectronics.

Lead halide perovskite micro-devices such as microplates and microwires have shown great potential in microlasers, especially in the “green gap” wavelength region of conventional semiconductors. However, the synthesized perovskite lasers are usually randomly distributed on the substrate, making their laser emissions hard to be collected and utilized. Here we demonstrate a simple way to efficiently couple perovskite microlasers into conventional single mode fibers. By attaching a perovskite microwire onto a tapered fiber via micromanipulation, we found that the emissions along the single mode fiber are more than an order of magnitude larger than the collected emission with a 40× objective lens (NA = 0.6). The detailed estimation shows that the experimentally measured collection efficiency at one end of the tapered fiber can be around 13–20%, which is good enough for practical applications. Our numerical calculations show that the collection is mainly induced by the diffraction at the end of the microwire instead of the evanescent coupling and the total coefficient at the two ends can be further improved by optimizing the tapered fiber and microwire. As the tapered fiber is drawn from a commercial single-mode fiber, this research clearly shows the potential of perovskite devices to be integrated with conventional fiber systems.

All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. Here, we experimentally demonstrate a silicon based large-scale magnetic metamaterial, which is fabricated with standard photolithography and conventional reactive ion etching process. The periodically arrayed silicon sub-wavelength structures possess electric and magnetic responses with low loss in mid-infrared wavelength range. We investigate the electric and magnetic resonances dependencies on the structural parameters and demonstrate the possibility of obtaining strong dielectric-based magnetic resonance through a broad band range. The optical responses are quite uniform over a large area about 2 × 2 cm2. The scalability of this design and compatibility fabrication method with highly developed semiconductor devices process could lead to new avenues of manipulating light for low-loss, large-area and real integrated photonic applications.