Abstract Soft photonic liquid crystals with electrically responsive properties are among the most promising intelligent materials for optoelectronic applications. This work demonstrates an ultra‐fast ...electrically tunable dual‐mode laser by introducing dye‐doped chiral liquid crystals. Due to the strong chirality of the chiral liquid crystal, two self‐assembled structures form depending on the temperatures. One is the chiral nematic phase (N*) with a 1D helical structure; the other is the blue phases (BPs) with 3D cubic structures. By tuning the strength of an electric field, the dye‐doped chiral liquid crystals are operated in two different modes: a band‐edge laser and a random laser. In the band‐edge mode, due to the electrostriction effect of the BPs, the electric‐tuning range of the laser emission is from 537 to 645 nm, and the switching times are less than 20 ms. When the electric field goes beyond a threshold value to force the occurrence of the BPs‐chiral‐nematic transition, the band‐edge laser with elliptical polarization emission is switched to a random laser with an immediate unpolarization emission (0.9 ms). Furthermore, the reversibility of the effects mentioned above points out the potential applications of self‐assembled soft photonic materials, spanning from solid‐state lighting to bio‐imaging.
Coronavirus disease 2019 (COVID‐19) can lead to pulmonary fibrosis due to the inflammatory process in the lung, resulting in a series of respiratory consequences. Patients with underlying systemic ...diseases or pre‐existing pulmonary diseases are particularly at risk of severe respiratory distress and persistent pulmonary abnormalities. Pirfenidone, a well‐known anti‐fibrotic agent recognized for its therapeutic effect on idiopathic pulmonary fibrosis, could be a feasible option in severe COVID‐19 cases given the similar pathophysiological features shared with interstitial lung diseases. In this paper, we share our experience of early administration of pirfenidone in combination with tofacitinib in a 61‐year‐old female patient with severe COVID‐19 pneumonia. Pirfenidone was initiated because of persistent dependence on high‐flow oxygen support and even the requirement for mechanical ventilation due to disease progression after initial standard COVID‐19 treatment. The patient was successfully extubated 15 days after the initiation of pirfenidone, and 13 days after extubation, she was completely weaned off supplemental oxygen. A series of chest radiographs and computed tomography scans demonstrated notable improvements in her lung condition. We propose a strategy of using pirfenidone plus tofacitinib as a rescue therapy in the management of patients with severe COVID‐19.
This study presents investigations into the fabrication, characterization, and performance analysis of stretchable white random lasers based on 2D glutamine(GLN)‐functionalized WS2 quantum dots (QDs) ...enhanced by the integration of Au nanoparticles (NPs) and a wrinkled graphene structure. Wrinkled graphene holds the potential for achieving transient population inversion through electron collisions. Incorporating Au NPs introduces localized surface plasmon resonance (LSPR), which enhances the light‐matter interaction, resulting in reduced lasing thresholds. The GLN‐functionalized WS2 QDs exhibit strong photoluminescence emission, and their integration with a wrinkled graphene structure and Au NPs creates a synergistic effect that enhances the emission efficiency and enables the realization of white random lasing. The extensive characterization and analysis of the emission spectra under different deformation ratios provide valuable insights into the tunability and reliability of these devices, as well as the importance of light trapping due to the wrinkled graphene structure. The findings of this study underscore the significant potential of LSPR and wrinkled graphene structure induced stretchable and white random lasers based on 2D GLN‐functionalized WS2 QDs. These lasers may have a promising application in the field of flexible and wearable photonics, which is a critical step towards the development of next‐generation optoelectronic devices with improved performance.
Wrinkled graphene structure and localized surface plasmon resonance induced stretchable white random lasers have been demonstrated and their excellent capability for potential applications in the next‐generation information technology.
Chiral nematic liquid crystals possess a one-dimensional periodic helical structure and are one of the oldest known materials with the ability of selective reflection of light. Their helix ...orientation, determining their optical properties, can be changed by a variety of stimuli, and it is also dominated by the surface treatment, ratio of the elastic constants and cell thickness. Here, we present a simple method to realize an angular independence reflective state, induced by a stable disturbed planar texture, in a surface-treatment-free chiral nematic liquid crystal cell. The scattering state caused by the defect-rich focal-conic texture can be electrically tuned to the reflective state from the disturbed planar texture in a very short time, and vice versa. These two optical conditions are both stable states in the null field until the next trigger. We find that the disturbed planar texture in the chiral nematic can provide a 100° viewing angle without reflected wavelength shift. The gray level of the reflected intensity can be tuned via application of the voltage pulses. Moreover, in this work, we discuss the effect of the chiral concentration on stabilizing the disturbed planar texture. When the chiral concentration is higher to induce the blue phases, the change in the texture of the ChNLCs after removing the strong electric field can stop at the disturbed planar texture with high reflectivity. In this work, the optical performance and the bistability based on the disturbed planar texture exhibits great potential for many applications, such as tunable filters, see-through/reflective displays and large-area smart windows.
Efficient photocatalytic dye degradation has been realized based on the first attempt of using a random laser. In previous studies, most photocatalytic dye degradation was conducted by using ...broad-angular emission lamps, light-emitting diodes, and conventional lasers. However, these types of light sources could be restricted by some disadvantages, such as weak intensity or high directionality. Unlike traditional lasers, random lasers obviate the need for the cavity. The advantage of broad-angular emission lights and the feature of laser-level intensity make random lasers a promising light source for many potential applications. In this study, an ultraviolet random laser (UVRL) derived from zinc oxide (ZnO) was used in the photocatalytic dye degradation experiment. It is found that the degradation efficiency of the UVRL is much better than that of conventional lasers and ultraviolet light-emitting diodes. The success of applying random laser systems in the photocatalytic reaction is expected to expand the applications of random lasers.
Hyperbolic metamaterial (HMM) has attracted considerable attention due to its enhanced light-matter interaction for tuning the photonic density of states and producing bulk plasmon polariton (BPP). ...In this study, we demonstrate the application of HMM in organic solar cells (OSCs) with superior performance for the first time. The designed HMM structure composed of multiple pairs of MoO
3
/Au stacks possesses a hyperbolic dispersion behavior in the primary light absorption regime of the photoactive material. To effectively couple BPP into the photoactive layer, the first pair of the HMM structure is designed to be a portion of the OSC structure, serving as the hole transport layer and anode. The unconventional HMM incorporated OSCs (HMM-OSCs) exhibit ∼29.4% enhancement in the power conversion efficiency (PCE) relative to similar OSCs using one pair of MoO
3
/Au and ∼11% improvement in PCE as compared to conventional OSCs with the fully reflective electrode. Compared to conventional OSCs, the performance improvement is primarily from the improved short circuit current density from a broad wavelength range of the enhanced photon-to-charge conversion efficiency due to the higher exciton generation and dissociation probability, as suggested by the photocurrent analysis and steady-state photoluminescence measurements. The experimental observation agrees well with that inferred from theoretical simulation for the enhancement in the local electric field and exciton generation rate for the designed HMM structure. Therefore, the designed HMM-OSCs can successfully couple BPP into operation with a large impact on light absorption efficiency enhancement. Our design principle can serve as a useful guideline for the application of HMM in other optoelectronic devices.
An unconventional organic solar cell structure based on hyperbolic metamaterials (HMMs) was designed, fabricated, and demonstrated with improved performance for the first time.
Abstract This study presents investigations into the fabrication, characterization, and performance analysis of stretchable white random lasers based on 2D glutamine(GLN)‐functionalized WS 2 quantum ...dots (QDs) enhanced by the integration of Au nanoparticles (NPs) and a wrinkled graphene structure. Wrinkled graphene holds the potential for achieving transient population inversion through electron collisions. Incorporating Au NPs introduces localized surface plasmon resonance (LSPR), which enhances the light‐matter interaction, resulting in reduced lasing thresholds. The GLN‐functionalized WS 2 QDs exhibit strong photoluminescence emission, and their integration with a wrinkled graphene structure and Au NPs creates a synergistic effect that enhances the emission efficiency and enables the realization of white random lasing. The extensive characterization and analysis of the emission spectra under different deformation ratios provide valuable insights into the tunability and reliability of these devices, as well as the importance of light trapping due to the wrinkled graphene structure. The findings of this study underscore the significant potential of LSPR and wrinkled graphene structure induced stretchable and white random lasers based on 2D GLN‐functionalized WS 2 QDs. These lasers may have a promising application in the field of flexible and wearable photonics, which is a critical step towards the development of next‐generation optoelectronic devices with improved performance.
Coronavirus disease 2019 (COVID-19) can lead to pulmonary fibrosis due to the inflammatory process in the lung, resulting in a series of respiratory consequences. Patients with underlying systemic ...diseases or pre-existing pulmonary diseases are particularly at risk of severe respiratory distress and persistent pulmonary abnormalities. Pirfenidone, a well-known anti-fibrotic agent recognized for its therapeutic effect on idiopathic pulmonary fibrosis, could be a feasible option in severe COVID-19 cases given the similar pathophysiological features shared with interstitial lung diseases. In this paper, we share our experience of early administration of pirfenidone in combination with tofacitinib in a 61-year-old female patient with severe COVID-19 pneumonia. Pirfenidone was initiated because of persistent dependence on high-flow oxygen support and even the requirement for mechanical ventilation due to disease progression after initial standard COVID-19 treatment. The patient was successfully extubated 15 days after the initiation of pirfenidone, and 13 days after extubation, she was completely weaned off supplemental oxygen. A series of chest radiographs and computed tomography scans demonstrated notable improvements in her lung condition. We propose a strategy of using pirfenidone plus tofacitinib as a rescue therapy in the management of patients with severe COVID-19.
A 10-Gb/s on-chip 1-D eye-opening monitor (EOM) for receiver front-end equalizer boost gain adaptations is presented. The proposed EOM circuits report in real-time horizontal eye-openings using ...equalizer output by calculating the probability density of the waveform in the central row of pixels of the eye diagram. In addition, a novel multi-phase generator circuit with a delay gain calibration is also demonstrated. It is suitable for EOM circuits to generate a multi-phase sampling clock. The proposed 1-D-EOM circuit is included in a 10-Gb/s receiver design to verify its adaptation functions, and the circuit is implemented using the 65-nm CMOS technology. The sampling phase resolution is 1.5625 ps (where the time for one bit is 100 ps, with a total of 64 phases), and the response time is 64 μs. The total power consumption of the EOM circuit is 1.5 mW with a 1-V supply voltage, and the circuit occupies a layout area of 60 μm × 450 μm. The results show that the reported horizontal eye-opening value is proportional to the value from a real eye diagram monitor from the test buffer.
A 5-bit 400-MHz time-domain analog-to-digital converter (ADC) was implemented in 0.18-μm CMOS technology. The proposed design is composed of a voltage-to-time-difference converter, a flash-type ...time-to-digital converter, and some error correction logic. Input voltage-type signals are converted to time-difference signals by a voltage-to-time-difference converter. Its rising- and falling-edge outputs contain delay information; they can then be converted by two time-to-digital converters operating at interleaving clock phases. Because of the transparent delayed signal without a sample-and-hold circuit, the subsequent time-to-digital converter structure is of the flash type. By using a distinct RC time constant of the time comparator, the time-difference signals can be converted to the relevant 1-of-n code. Because this conversion is almost entirely digital in nature, little static current is consumed. The measured signal to noise and distortion ratio and spurious-free dynamic range of the ADC are 26.1 dB and 31.5 dB, respectively, at a 400-MHz sampling frequency for a 100-MHz input signal.
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