Senolytic Therapy Enabled by Senescent Cell-Sensitive Biomimetic Melanin Nano-Senolytics.

Cellular senescence is a significant risk factor for aging and age-related diseases (ARD). The canonical senolytics Dasatinib and Quercetin (DQ) have shown promise in clearing senescent cells (SnCs); however, the lack of selectivity poses a challenge in achieving optimal outcomes. Despite the recent occurrence of nanomaterial-based approaches targeting SnCs, limited therapeutic effects, and potential toxicity still remain a major concern. Herein, a "double locks-like" nanoplatform is developed that integrated Galactan coating and mesoporous polydopamine to encase the senolytic drug DQ. By this way, DQ is only released in SnCs that are featured with higher levels of ß-galactosidase (ß-gal) and low PH. Additionally, the nanoparticles are equipped with 2,2,6,6-Tetramethylpiperidine-1-oxyl (Tempo) to gain enhanced photothermal converting potential. Consequently, the synthesized nanosenolytics demonstrate remarkable specificity and efficacy in eradicating SnCs, and accordingly reverse pulmonary fibrosis in mice without affecting normal tissues. Upon exposure of near-infrared (NIR) light, the nanoparticles demonstrate to efficiently remove senescent tumor cells inducted by chemotherapy, thereby hindering the outgrowth and metastasis or breast cancer. Collectively, the present study develops an "On/Off" switchable nanoplatform in response to SnCs, and produces a more safe, efficient, and feasible way to delay aging or alleviate age-associated diseases.

Modulation of alveolar macrophage and mitochondrial fitness by medicinal plant-derived nanovesicles to mitigate acute lung injury and viral pneumonia.

Acute lung injury (ALI) is generally caused by severe respiratory infection and characterized by overexuberant inflammatory responses and inefficient pathogens-containing, the two major processes wherein alveolar macrophages (AMs) play a central role. Dysfunctional mitochondria have been linked with distorted macrophages and hence lung disorders, but few treatments are currently available to correct these defects. Plant-derive nanovesicles have gained significant attention because of their therapeutic potential, but the targeting cells and the underlying mechanism remain elusive. We herein prepared the nanovesicles from Artemisia annua, a well-known medicinal plant with multiple attributes involving anti-inflammatory, anti-infection, and metabolism-regulating properties. By applying three mice models of acute lung injury caused by bacterial endotoxin, influenza A virus (IAV) and SARS-CoV-2 pseudovirus respectively, we showed that Artemisia-derived nanovesicles (ADNVs) substantially alleviated lung immunopathology and raised the survival rate of challenged mice. Macrophage depletion and adoptive transfer studies confirmed the requirement of AMs for ADNVs effects. We identified that gamma-aminobutyric acid (GABA) enclosed in the vesicles is a major molecular effector mediating the regulatory roles of ADNVs. Specifically, GABA acts on macrophages through GABA receptors, promoting mitochondrial gene programming and bioenergy generation, reducing oxidative stress and inflammatory signals, thereby enhancing the adaptability of AMs to inflammation resolution. Collectively, this study identifies a promising nanotherapeutics for alleviating lung pathology, and elucidates a mechanism whereby the canonical neurotransmitter modifies AMs and mitochondria to resume tissue homeostasis, which may have broader implications for treating critical pulmonary diseases such as COVID-19.

RAB10 Facilitates Colorectal Cancer Progression through Activation of the NF-κB Signaling Pathway.

Background: Colorectal cancer (CRC) is the third most prevalent malignancy globally, ranking as the second leading cause of cancer-related mortality. Emerging evidence highlights RAB10's involvement in the progression of various malignant tumors; however, its specific role in CRC remains unclear. Objective: To explore the oncogenic role of RAB10 in colorectal cancer progression by investigating its impact on NF-κB activation, aiming to identify a novel genetic biomarker for enhanced diagnosis and treatment of CRC. Methods: This study collected CRC tissue samples and utilized The Cancer Genome Atlas (TCGA) database for RAB10 expression verification through Western blot (WB). Cellular phenotype experiments were conducted on CRC cell lines, including quantitative real-time-polymerase chain reaction (qRT-PCR), CCK-8, transwell assay, and wound healing assay (HCT116 and SW480). Additionally, the impact of RAB10 on NF-κB signaling was assessed through qRT-PCR and WB. Results: RAB10 exhibited upregulation in CRC tissue samples compared to normal counterparts. Furthermore, RAB10 promoted the proliferation, migration, and invasion of HCT116 and SW480 cells. Notably, RAB10 induced NF-κB activation in CRC in vitro. Conclusion: This study revealed the oncogenic function of RAB10, explaining its role in activating NF-κB in CRC. The findings present RAB10 as a potential genetic biomarker for CRC diagnosis and treatment.

Colorectal cancer subtyping and prognostic model construction based on interleukin-related genes.

Members of the interleukin (IL) family are closely linked to cancer development and progression. However, research on the prognosis of colorectal cancer (CRC) related to IL is still lacking. This study investigated new CRC prognostic markers and offered new insights for CRC prognosis and treatment. CRC-related data and IL gene data were collected from public databases. Sample clustering was done with the NMF package to divide samples into different subtypes. Differential, enrichment, survival, and immune analyses were conducted on subtypes. A prognostic model was constructed using regression analysis. Drug sensitivity analysis was performed using GDSC database. Western blot analysis was performed to assess the effect of IL-7 on the JAK/STAT signaling pathway. Flow cytometry was used to examine the impact of IL-7 on CD8+ T cell apoptosis. Two CRC subtypes based on IL-associated genes were obtained. Cluster 1 had a higher survival rate than cluster 2, and they showed differences in some immune levels. The two clusters were mainly enriched in the JAK-STAT signaling pathway, T helper 17 cell differentiation, and the IL-17 signaling pathway. An 11-gene signature was built, and risk score was an independent prognosticator for CRC. The low-risk group showed a higher sensitivity to nine common targeted anticancer drugs. Western blot and flow cytometry results demonstrated that IL-7 could phosphorylate STAT5 and promote survival of CD8+ T cells. In conclusion, this study divided CRC samples into two IL-associated subtypes and obtained an 11-gene signature. In addition, targeted drugs that may improve the prognosis of patients with CRC were identified. These findings are of paramount importance for patient prognosis and CRC treatment.NEW & NOTEWORTHY We identified two clusters with significant survival differences in colorectal cancer (CRC) based on interleukin-related genes, constructed an 11-gene risk score model that can independently predict the prognosis of CRC, and explored some targeted drugs that may improve the prognosis of patients with CRC. The results of this study have important implications for the prognosis and treatment of CRC.

Establishment and validation of a prognostic nomogram for patients with colorectal neuroendocrine carcinoma.

BACKGROUND: Colorectal neuroendocrine carcinoma is a relatively rare tumor, for which a prognosis prediction model is lacking. Based on the data from Surveillance, Epidemiology, and End Results (SEER) database and Fujian Cancer Hospital, the study constructed and validated a prognostic nomogram to assess overall survival of patients with colorectal neuroendocrine carcinoma(CRNEC). METHODS: We extracted data of patients diagnosed with CRNEC from the SEER database. These patients were randomly divided into a training cohort(N = 1425) and an internal validation cohort(N = 612). Data of patients diagnosed with CRNEC in Fujian Cancer Hospital was collected as an external validation cohort(N = 54). A prognostic nomogram was established. The performance of the nomogram was assessed with ROC curve, C-index and calibration curve. Decision curve analysis(DCA) and ROC curve were used to compare the prediction efficacy of nomogram with the seventh edition of the TNM classification of the American Joint Commission of Cancer. RESULTS: Nine variables were identified as independent predictors. Nomogram were established by the nine variables. AUC of the nomogram in predicting 1-, 3- and 5-year OS were 0.900, 0.912 and 0.915 in training cohort, 0.900, 0.925 and 0.919 in internal validation cohort, 0.900, 0.903 and 0.928 in external validation cohort. C-index were 0.845, 0.854 and 0.837. Calibration curves overlapped well with reference lines. Compared with the AJCC TNM staging system, the nomogram performed more effectively. Patients classified into low-risk and high-risk groups by the nomogram scores and performed well in stratification. CONCLUSION: The prognostic nomogram established and validated in our study can accurately and effectively predict the prognosis of patients with CRNEC.

Genome-wide phylogenetic and genetic evolutionary analyses of mitochondria in Hypoderma bovis and H. sinense on the Qinghai-Tibetan Plateau.

Hypoderma bovis (H. bovis) and Hypoderma sinense (H. sinense) are insects that cause hypodermosis in yaks and Bos taurus. Hypodermosis is a severe skin condition that not only impairs the development of local animal husbandry but also poses threats to human health as a zoonosis. The Qinghai-Tibetan Plateau (QTP) is known as the "Roof of the World." Its unique geographical environment and climate conditions have supported the growth of a wide range of mammals, providing favorable conditions for Hypoderma spp. to complete their life cycles. In this study, the whole mitochondrial genomes of H. bovis and H. sinense collected from the QTP were sequenced and phylogenetically analyzed. We found that the whole genomes of H. bovis and H. sinense are 16,283 bp and 16,300 bp in length, respectively. Both the H. bovis and H. sinense genomes have 37 mitochondrial genes, which include two rRNA genes (16S rRNA and 12S rRNA), 22 tRNA genes, the control region (D-loop region), the light chain replication initiation region, and 13 protein-coding genes (PCGs). The phylogenetic tree generated based on the 13 PCGs revealed close phylogenetic relationships between H. sinense, H. bovis, and Hypoderma lineatum. A similar result was also found in our phylogenetic analysis based on 18S rRNA and 28S rRNA. However, analysis of cytochrome oxidase subunit I (COI) showed cluster of H. bovis, H. sinense, and Cuterebra spp. on the same branch, all belonging to Oestridae. The differentiation time generated based on 13 PCGs indicates that H. bovis and H. sinense differentiated and formed ~4.69 million years ago (Mya) and ~4.06 Mya, respectively. This timing coincides with the differentiation and appearance of yak and Bos taurus in the Pliocene (~4.7 Mya), indicating that the parasites and mammals diverged in close temporal proximity. Of note, this period also witnessed a rapid uplift of the QTP, causing significant climate and environmental changes. Thus, we conjecture that the differentiation of Hypoderma spp. is potentially related to the differentiation of their host species, as well as climate changes caused by the uplift of the QTP. Overall, our study can provide valuable data to support further studies on the phylogeny and differentiation of Hypoderma spp. on the QTP.

Activin A/ACVR2A axis inhibits epithelial-to-mesenchymal transition in colon cancer by activating SMAD2.

Colorectal cancer is one of the most common malignancies worldwide. Liver metastasis is the major direct cause of colorectal cancer-related deaths. Although radical resection is the most effective treatment for colorectal cancer liver metastasis, several patients are not eligible for surgery. Therefore, there is a need to develop novel treatments based on the understanding of the biological mechanisms underlying liver metastasis in colorectal cancer. This study demonstrated that activin A/ACVR2A inhibits colon cancer cell migration and invasion, as well as suppresses the epithelial-to-mesenchymal transition of mouse colon cancer cells. This finding has been further validated in animal experiments. Mechanistic studies revealed that activin A binds to Smad2 (instead of Smad3) and activates its transcription. Analysis of the paired clinical samples further confirmed that the expression levels of ACVR2A and SMAD2 were the highest in adjacent healthy tissues, followed by primary colon cancer tissues and liver metastasis tissues, suggesting that ACVR2A downregulation may promote colon cancer metastasis. Bioinformatics analysis and clinical studies demonstrated that ACVR2A downregulation was significantly associated with liver metastasis and poor disease-free and progression-free survival of patients with colon cancer. These results suggest that the activin A/ACVR2A axis promotes colon cancer metastasis by selectively activating SMAD2. Thus, targeting ACVR2A is a potential novel therapeutic strategy to prevent colon cancer metastasis.

Characterization and complete genome sequence analysis of the novel phage RPZH3 infecting Ralstonia solanacearum.

A novel lytic Ralstonia phage, RPZH3, was isolated from the soil of a tobacco field via a double agar overlay plaque assay. The phage has an icosahedral head 75 ± 5 nm in diameter with a short tail about 15 ± 5 nm in length. It was able to infect 18 out of 30 tested strains of R. solanacearum isolated from tobacco, sweet potato, tomato, pepper, and eggplant. The latent period of the phage was 80 min, and the burst period was 60 min with a burst size of about 27 pfu/cell. The phage was stable at pH 4-12 at 28°C, and it was also stable at temperatures from 45°C to 60°C at pH 7.0. The complete genome of phage RPZH3 consists of 65,958 bp, with a GC content of 64.93%. The genome contains 93 open reading frames (ORFs) and encodes a tRNA for cysteine. Nucleotide sequence alignment and phylogenetic analysis indicated that RPZH3 is a new member of the genus Gervaisevirus belonging to the class Caudoviricetes.

Tandem mass tag labeled quantitative proteomic analysis of differential protein expression on total alkaloid of Aconitum flavum Hand.-Mazz. against melophagus ovinus.

Melophagus ovinus disease is a common ectoparasitosis, which can lead to a decrease in animal production performance, product quality, and even death. Aconitum flavum Hand.-Mazz. has many pharmacological activities including insecticidal, heat-clearing, analgesic, and dehumidifying. However, there are few researches focused on the effects and related mechanism of Aconitum flavum Hand.-Mazz. in killing Melophagus ovinus. In this study, 11 alkaloids of Aconitum flavum Hand.-Mazz. were detected, and its total alkaloid activity was determined. The results showed when the total alkaloid concentration was 64 mg/ml and the treatment time was 16 h, the killing rate of Melophagus ovinus reached 100%. Through the observation of the differences in the surface of Melophagus ovinus in each experimental group, it was found that the morphology of the posterior end of the female Melophagus ovinus in the alkaloid treatment group was significantly different from that of the blank and positive control groups, and most of the epidermal tissue was obsessive and missing. Moreover, the enzyme activity determination results of 64 mg/ml group were significantly different when compared with the normal control group, while there was no significant difference in other groups. Then, the Melophagus ovinus gene library was established by the unreferenced genome transcriptome sequencing, the proteomic comparison was performed using tandem mass tag labeled protein detection technology, and finally, the samples were quantitatively analyzed by liquid chromatography-mass spectrometry tandem and bioinformatics methods. Based on the above experimental results, it was speculated that Aconitum flavum Hand.-Mazz. total alkaloids may cause the imbalance of protein disulfide isomerase expressions by affecting the regulation of Hsp40 cellular protein homeostasis and the oxidation of protein disulfide isomerase and related proteins. This would affect the selective recognition of signal sequence, the targeted transport of Sec 61, and the correct folding of the three-dimensional structure of amino acid chain, weakening the clearance of amino acid chains that cannot be correctly folded and eventually resulting in the killing of Melophagus ovinus. This study preliminarily revealed the mechanism of Aconitum flavum Hand.-Mazz. total alkaloids against Melophagus ovinus and provided a theoretical basis for the screening of Melophagus ovinus action targets and the development of new veterinary drugs.

Delay and Packet-Drop Tolerant Multistage Distributed Average Tracking in Mean Square.

This article studies the distributed average tracking (DAT) problem pertaining to a discrete-time linear time-invariant multiagent network, which is subject to, concurrently, input delays, random packet drops, and reference noise. The problem amounts to an integrated design of delay and a packet-drop-tolerant algorithm and determining the ultimate upper bound of the tracking error between agents' states and the average of the reference signals. The investigation is driven by the goal of devising a practically more attainable average tracking algorithm, thereby extending the existing work in the literature, which largely ignored the aforementioned uncertainties. For this purpose, a blend of techniques from Kalman filtering, multistage consensus filtering, and predictive control is employed, which gives rise to a simple yet comepelling DAT algorithm that is robust to the initialization error and allows the tradeoff between communication/computation cost and stationary-state tracking error. Due to the inherent coupling among different control components, convergence analysis is significantly challenging. Nevertheless, it is revealed that the allowable values of the algorithm parameters rely upon the maximal degree of an expected network, while the convergence speed depends upon the second smallest eigenvalue of the same network's topology. The effectiveness of the theoretical results is verified by a numerical example.

Nanostructure enabled lower on-state resistance and longer lock-on time GaAs photoconductive semiconductor switches.

We report a new, to the best of our knowledge, type of SI-GaAs photoconductive semiconductor switch (PCSS) with nanostructures. Since light can enter from both the top and side surfaces of nanostructures, the effective penetration depth is significantly increased. Lower on-state resistance and a longer lock-on time have been achieved in the nonlinear mode with this design, as well as a lower triggering fluence in the linear mode. This could be highly useful for a variety of applications that require lower on-state resistance and/or longer lock-on time such as pulsed power systems and firing set switches.

Anomalous bi-directional scanning electro-optic KTN devices with UV-assisted electron and hole injections.

In this Letter, we reported anomalous electro-optic potassium tantalate niobate (KTN) devices, in which both electrons and holes were injected into the KTN crystal via ultraviolet (UV) illumination-assisted charge injection. This could not only significantly enhance the performance of electro-optic devices (e.g., a 270% increase in the deflection angle in terms of the KTN deflector) but also enable the new bi-directional scanning capability. The results in this work would be very useful for a variety of devices and applications, such as electro-optic based vari-focal lenses.

Analysis on the electric field distribution in a relaxor ferroelectric KTN crystal near field-induced phase transition using optical deflection measurements.

Spatially analyzing non-uniform distributions of electric phenomena such as electric field and permittivity in ferroelectric devices is very challenging. In this study, we apply an optical beam deflection method to map the non-uniform electric phenomena in relaxor ferroelectric potassium tantalate niobate (KTN) crystals. To adequately correlate the physical parameters and their spatial distributions in KTN crystals, a general model that describes the giant electro-optic response and associated beam deflection is derived. The proposed model is in good agreement with the experimental results and is envisioned to be useful for analyzing electric field-induced phenomena in non-linear dielectric materials and devices.

[Down-regulation of miR-205-5p enhances pro-apoptotic effect of 3-bromopyruvate on human nasopharyngeal carcinoma CNE2Z cells].

OBJECTIVE: To investigate the effect of down-regulation of miR-205-5p on 3-bromopyruvate-induced apoptosis in human nasopharyngeal carcinoma CNE2Z cells. METHODS: Nasopharyngeal carcinoma CNE2Z cells were transfected with miR- 205-5p-mimic or miR-205-5p-inhibitor, treated with 80 µmol/L 3-bromopyruvate alone, or exposed to both of the treatments. The proliferation of the treated cells was examined with MTT assay, and early apoptosis of the cells was detected using a mitochondrial membrane potential detection kit (JC-1). DAPI fluorescence staining was used to detect morphological changes of the cell nuclei and late cell apoptosis; Annexin V-FITC/PI double staining was employed to detect the cell apoptosis rate. Western blotting was used to detect the expressions of Bcl-2, Bax, Mcl-1 and Bak proteins. RESULTS: Exposure to 3-bromopyruvate significantly inhibited the proliferation of CNE2Z cells, and increasing the drug concentration and extending the treatment time produced stronger inhibitory effects. Treatment with 80 µmol/L 3-bromopyruvate for 24, 48 and 72 h resulted in inhibition rates of (45.7±1.21)%, (64.4±2.02)% and (78.3±1.55)% in non-transfected CNE2Z cells, respectively; the inhibition rates were (27.7±1.04)%, (34.8±2.10)% and (44.3±1.57)% in the cells transfected with miR-205-5p-mimic, and were (80.5 ± 0.94)%, (87.9 ± 0.50)% and (93.8 ± 1.16)% in cells transfected with miR-205-5p-inhibitor, respectively. The results of mitochondrial membrane potential detection showed that the relative proportion of red and green fluorescence decreased significantly in miR-205-5p-inhibitor-transfected cells with 3-bromopyruvate treatment. Combined treatment of the cells with 3-bromopyruvate and miR-205-5p-inhibitor transfection obviously increased nuclear fragmentation and nuclear pyknosis and significantly increased cell apoptotic rate as compared with the two treatments alone (P < 0.01), causing also decreased expressions of Bcl-2 and Mcl-1 proteins and increased expressions of Bax and Bak proteins. CONCLUSIONS: Inhibition of miR-205-5p enhances the proapototic effect of 3-bromopyruvate in CNE2Z cells possibly in relation to the down-regulation of Mcl-1 and Bcl-2 and the up-regulation of Bak and Bax proteins.

Enhanced electro-optic beam deflection of relaxor ferroelectric KTN crystals by electric-field-induced high permittivity.

Most applications of a ferroelectric-based electro-optic (EO) beam deflector have been limited by the high applied voltage. In this Letter, we report a dramatically increased EO beam deflection in relaxor ferroelectric potassium tantalate niobate (KTN) crystals by using the electric-field-enhanced permittivity. Due to the existence of the electric-field-induced phase transition in relaxor ferroelectric materials, the dielectric permittivity can be substantially increased by the applied electric field at a certain temperature. Both the theoretical study and the experimental verifications on the enhanced beam deflection and EO effect in the case with the electric-field-induced high permittivity were conducted. The experimental results confirmed that there was a three-fold increase in the deflection angle, which represented a dramatic increase in the deflection angle. By offering a wider deflection range and a lower driving voltage, such a largely enhanced beam deflection is of great benefit to the KTN deflector.

Enhanced electro-optic beam deflection of relaxor ferroelectric KTN crystals by electric-field-induced high permittivity: publisher's note.

This publisher's note contains corrections to Opt. Lett.44, 5557 (2019)OPLEDP0146-959210.1364/OL.44.005557.

Ruby fluorescence-enabled ultralong lock-on time high-gain gallium arsenic photoconductive semiconductor switch.

We report a new type of photoconductive semiconductor switch (PCSS), consisting of a semi-insulating gallium arsenic (GaAs) substrate and a front-bonded ruby crystal. The 532 nm laser pulses from an Nd-YAG laser incident on the front surface of the ruby crystal. A portion of the laser pulse passes through the crystal and reaches the GaAs substrate, and the remaining portion of the laser pulse is absorbed by the ruby crystal. This results in the emission of 694 nm fluorescent light. Furthermore, a portion of emitted fluorescent light also reaches the GaAs substrate. The high-fluence 532 nm short laser pulse with a pulse width around several nanoseconds is used to trigger the PCSS entering the high-gain nonlinear mode, whereas the low-fluence long-lifetime (on the order of a millisecond) 694 nm fluorescent light is used to maintain the lock-on time. Thus, an ultralong lock-on time on the order of millisecond is achieved, which is 3 orders of magnitude longer than a typical lock-on time of high-gain GaAs PCSS.

Chemokine (C-X-C motif) ligand 1 is associated with tumor progression and poor prognosis in patients with colorectal cancer.

Chemokine (C-X-C motif) ligand 1 (CXCL1) is a chemotactic cytokine known to regulate cancer progression and invasion. However, the prognostic significance of CXCL1 expression in colorectal cancer (CRC) has not been fully characterized. The present study explored the clinicopathological significance and potential role of CXCL1 in the carcinogenesis and progression of CRC. The protein expression of CXCL1 was measured immunohistochemically in tissue microarrays constructed from 276 CRC patients. CXCL1 expression levels and their associations with clinicopathological characteristics and patient survival were evaluated. The effect of CXCL1 on glycolysis was also examined. High CXCL1 expression was detected in 165 (59.8%) cases. CXCL1 expression was correlated with tumor diameter (P=0.002), T stage (P=0.044), N stage (P=0.005), M stage (P=0.001), lymphovascular invasion (P=0.010), and carcinoembryonic antigen status (P=0.019). High CXCL1 expression was validated as an independent prognostic factor for overall survival (OS) and disease-free survival (DFS) by both univariate and multivariate Cox regression analyses (both P<0.05). Experimentally, expression of CXCL1 was knocked down by stable transfected short hairpin RNA, resulting in a significantly decreased rate of glycolysis both in in vitro assays and in patients' samples (P<0.05). Silencing the expression of CXCL1 decreased the levels of the glycolytic enzymes GLUT1, HK2, and LDHA. In conclusion, by inducing glycolysis, CXCL1 plays a crucial role in both cancer progression and metastasis in CRC patients. The CXCL1 expression level is an independent prognostic factor for both OS and DFS. Moreover, CXCL1 may serve as a new biomarker and potential therapeutic target for CRC treatment.

High speed non-mechanical two-dimensional KTN beam deflector enabled by space charge and temperature gradient deflection.

In this paper, a high-speed non-mechanical two-dimensional KTN beam deflector is reported. The scanning mechanism is based on the combination of space charge controlled beam deflection and temperature gradient enabled beam deflection in a nanodisordered KTN crystal. Both theoretical analyses and experimental investigations are provided, which agree relatively well with each other. This work provides an effective way for realizing multi-dimensional high-speed non-mechanical beam deflection, which can be very useful for a variety of applications, including high-speed 3D laser printing, high resolution high speed scanning imaging, and free space reconfigurable laser communications.

Three order increase in scanning speed of space charge-controlled KTN deflector by eliminating electric field induced phase transition in nanodisordered KTN.

In this paper, we report a three orders-of-magnitude increase in the speed of a space-charge-controlled KTN beam deflector achieved by eliminating the electric field-induced phase transition (EFIPT) in a nanodisordered KTN crystal. Previously, to maximize the electro-optic effect, a KTN beam deflector was operated at a temperature slightly above the Curie temperature. The electric field could cause the KTN to undergo a phase transition from the paraelectric phase to the ferroelectric phase at this temperature, which causes the deflector to operate in the linear electro-optic regime. Since the deflection angle of the deflector is proportional to the space charge distribution but not the magnitude of the applied electric field, the scanning speed of the beam deflector is limited by the electron mobility within the KTN crystal. To overcome this speed limitation caused by the EFIPT, we propose to operate the deflector at a temperature above the critical end point. This results in a significant increase in the scanning speed from the microsecond to nanosecond regime, which represents a major technological advance in the field of fast speed beam scanners. This can be highly beneficial for many applications including high-speed imaging, broadband optical communications, and ultrafast laser display and printing.