Direct modulation of microcavity emission via local perturbation

Wang

Wei

et al. 2016

J. Phys. Chem. Lett.

Self Cite

The control of photoluminescence and absorption of lead halide perovskites plays a key role in their applications in micro- and nano-sized light emission devices and photodetectors. To date, the wavelength controls of lead halide perovskite microlasers are mostly realized by changing the halide mixture in solution. Herein, we report the postsynthetic and selective control of the optical properties of lead halide perovskites with conventional semiconductor technology. By selectively exposing a CHNHPbBr microstructure with chlorine in inductively coupled plasma, we find that the wavelengths of absorption, photoluminescence, and laser emissions of exposed structures are blue-shifted around 50 nm. Most importantly, the device characteristics such as the photoluminescence intensities and laser thresholds are well maintained during the reaction process. We believe our finding will significantly boost the practical applications of lead halide perovskite based optoelectronics.

mentioning

confidence: 99%

Postsynthetic and Selective Control of Lead Halide Perovskite Microlasers

Wang

Wei

et al. 2016

J. Phys. Chem. Lett.

Self Cite

“…[35, 38]. Here we applied a perturbation Δn on the circular cavity and studied the responses of propagating waves.…”

Section: Resultsmentioning

confidence: 99%

“…To confirm the chirality in circular disk, we analyzed the field distribution (Hz) by expanding the wave functions inside the cavity in cylindrical harmonics 15 38 , where J m is the m th-order Bessel function of the first kind. Positive and negative values of angular momentum m correspond to the CCW and CW propagating components, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Based on above researches, we then can control the chirality of circular cavity via changing local refractive index such as Ref. [ 35 , 38 ]. Here we applied a perturbation Δn on the circular cavity and studied the responses of propagating waves.…”

Section: Resultsmentioning

confidence: 99%

“…By introducing mode coupling into the chirality, we have also shown that the co-propagating directions of non-orthogonal mode pairs can be simply switched between CW and CCW directions. As the mode coupling can be easily controlled by changes of local refractive index 35 38 , the reverse of the propagating direction can be fulfilled by locally perturbing the cavity. Due to the dramatic change in K factor, the reverse of propagating direction is possible to be utilized to further improve the sensitivity of optical sensors.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

The combination of high Q factor and chirality in twin cavities and microcavity chain

Song

Zhai

et al. 2014

Sci Rep

Self Cite

Chirality in microcavities has recently shown its bright future in optical sensing and microsized coherent light sources. The key parameters for such applications are the high quality (Q) factor and large chirality. However, the previous reported chiral resonances are either low Q modes or require very special cavity designs. Here we demonstrate a novel, robust, and general mechanism to obtain the chirality in circular cavity. By placing a circular cavity and a spiral cavity in proximity, we show that ultra-high Q factor, large chirality, and unidirectional output can be obtained simultaneously. The highest Q factors of the non-orthogonal mode pairs are almost the same as the ones in circular cavity. And the co-propagating directions of the non-orthogonal mode pairs can be reversed by tuning the mode coupling. This new mechanism for the combination of high Q factor and large chirality is found to be very robust to cavity size, refractive index, and the shape deformation, showing very nice fabrication tolerance. And it can be further extended to microcavity chain and microcavity plane. We believe that our research will shed light on the practical applications of chirality and microcavities.

All‐Optical Modulation of Microcavity Emission by Parity‐Time Symmetry

Song

et al. 2020

Annalen der Physik

Integration of microcavity‐based coherent light sources and waveguides is of central importance for building optical networks and photonic circuits. However, such combined devices face severe challenges in distributing the generated signals to designed ends despite that the significant advances are accomplished in emission modulation and controlling. Herein, dynamically all‐optical control of the outputs from the microcavity by employing parity‐time (PT) symmetry is demonstrated. By exploiting the interplay between gain and loss in a waveguide‐connected microsquare cavity, the mode field distributions can be strongly modified when the non‐Hermitian system enters PT‐symmetry breaking phase. Numerical calculations and the corresponding Husimi projections unambiguously show the PT‐symmetry‐induced mode localization and output redistributions in microsquare cavity. Notably, the intensity ratios of the lights collected by the two channels can be directly tuned over two orders of magnitude with the increase of pumping strength. These findings will be essential for understanding the fundamentals of non‐Hermitian optics and advancing the application potentials of microcavity system in integrated photonics.