Search

By utilizing progress in millijoule-level pulsed fiber lasers operating in the 1.96 µm spectral range, we introduce a concept utilizing a spaceborne differential absorption barometric lidar designed to operate within the 1.96 µm CO2 absorption band for remote sensing of Martian atmospheric properties. Our focus is on the online wavelength situated in the trough region of two absorption lines, selected due to its insensitivity to laser frequency variations, thus mitigating the necessity for stringent laser frequency stability. Our investigation revolves around a compact lidar configuration, featuring reduced telescope dimensions and lower laser pulse energies. These adjustments are geared towards minimizing costs for potential forthcoming Mars missions. The core measurement objectives encompass the determination of column CO2 absorption optical depth, columnar CO2 abundance, surface atmospheric pressure, and vertical distributions of dust and cloud layers. Through the amalgamation of surface pressure data with atmospheric temperature insights garnered from sounders and utilizing the barometric formula, the prospect of deducing atmospheric pressure profiles becomes feasible. Simulation studies validate the viability of our approach. Notably, the precision of Martian surface pressure measurements is projected to surpass 1 Pa when the aerial dust optical depth is projected to be under 0.7, a typical airborne dust scenario on Mars, considering a horizontal averaging span of 10 km. [ABSTRACT FROM AUTHOR]

In recent years, 3D printing glass optics has gained massive attention in industry and academia since glass could be an ideal material to make optical elements, including the lens. However, the limitation of materials and printing methods has prevented 3D printing glass optics progress. Therefore, we have developed a novel printing strategy for germanate glass printing instead of pure silica. Moreover, compared with traditional multi-component quartz glass, germanate glass has unmatched advantages for its mid-infrared (MIR) transparency and outstanding visible light imaging performance. Furthermore, compared with non-oxide glass (fluoride glass and chalcogenide glass), germanate glass has much better mechanical, physical, and chemical properties and a high refractive index. Germanate glass has been widely applied in remote sensing, ranging, environmental detection, and biomedical detection. However, it is difficult to shape, cast, polish, and grind for optical and photonics applications such as imaging optics and laser-collimation optics. These drawbacks have made germanate glass inaccessible to complex optical elements and greatly increased their cost. In this report, we use germanate glass fibers with a diameter of 125 µm based on fiber-fed laser heating technology to fabricate an mm-size optical application. In this paper, we combine the fiber-fed laser heating technology with an optimized temperature control process to manufacture high-precision optical elements. Germanate glass optics can be printed with excellent visible light and IR transparency and a smooth surface with roughness under 4 nm. By optimizing the layer-by-layer 3D printing process and the thermal feedback in the printing process, we avoid cracks and minimize surface deformation. This work shows the possibility of the mm-size glass optical elements 3D printing and widens its application for IR optics. [ABSTRACT FROM AUTHOR]

Vast tunable optical components are realized based on dynamic reconfigurations of the incident wavefronts, such as beam steering and tunable lens. However, the dominant paradigm of current wavefront reconfiguration technologies relies on complex control systems with degrees of freedom much larger than output wavefronts, e.g., beam steering based on spatial light modulator or phased array antennas. Here, a new paradigm for dynamic reconfiguration of arbitrary output wavefronts using control systems with the same degrees of freedom is proposed. As an example, a wavefront transformer is demonstrated using an in‐plane two‐degree‐of‐freedom (2DOF) mechanical actuation system of metasurface doublet for semi‐omnidirectional beam steering, which measures a 6‐kHz modulation speed and a 131.2° × 131.2° field of view. This paradigm can be applied to metasurface transformers for dynamic wavefront reconfiguration with any control system for vast applications, such as tunable lens, beam steering, and dynamic beam profiler, just to name a few. [ABSTRACT FROM AUTHOR]

We developed a fiber laser based 515 nm single‐mode green laser with pulse width of 5 ns, peak power of greater than 20 kW, and repetition rates from 100 kHz to 500 kHz, which is suitable for glass drilling and grinding. The lithium triborate (LBO) crystal is used for second harmonic generation of 515 nm laser with efficiency of 68%. Glass drilling speed of 50 mm/s @ 0.5 mm thick glass was achieved for industrial environment continuous operation, which is equivalent to 1 s of time to drill a 4 mm diameter hole on a 2 mm thick glass. The typical chip sizes for the rear and front sides are 80 μm and 120 μm, respectively. Seven thousand holes are drilled in 24 hours in glass product line, and the success rate is larger than 99.7%. This laser glass drilling approach is rapidly accepted by glass industrial. Glass surface grinding was demonstrated by using 1 ns pulse width 515 nm lasers. [ABSTRACT FROM AUTHOR]

Paeoniflorin (PF) possesses multiple biological functions including anti-oxidization. PF is the major bioactive ingredient of total glycosides of paeony (TGP), which could promote re-pigmentation of vitiligo. The study was sought to investigate the effects and potential signaling pathways of PF on hydrogen peroxide (H2O2)-induced oxidative stress in melanocytes. The results showed that pretreatment with 50 µM PF significantly inhibited cell apoptosis, enhanced cell viability, and suppressed reactive oxygen species (ROS) accumulation by enhancing the productions of superoxide dismutase (SOD) and antioxidant enzymes catalase (CAT). Furthermore, PF activated c-Jun amino terminal kinase (JNK) and the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway to counteract H2O2-induced oxidative damage in PIG1 and PIG3V. Taken together, our study firstly demonstrates that PF resists H2O2-induced oxidative stress in melanocytes probably by activating JNK/Nrf2/HO-1 signaling, suggesting a potential therapeutic application of PF on vitiligo. [ABSTRACT FROM AUTHOR]

Background: Large-scale retrospective studies of light/laser in treating nasal rosacea were lacking. Objective: The study was aimed to perform a decade retrospection of the patients with nasal rosacea who were treated with light/laser devices. Methods: A study between 2008 and 2017 was performed retrospectively. Categorization of rosacea type (erythema/telangiectasia, ET; papules/pustules, PP; rhinophyma, RP) was made according to the photographs. Device settings, treatment regimens and treatment sessions of light/laser facilities were summarized. Efficacy was evaluated using a grading scale. Results: In all, 807 patients received light/laser treatments. The subtypes of nasal rosacea were ET (n = 196), PP (n = 95), RP (n = 42), ET + PP (n = 334), ET + RP (n = 15), PP + RP (n = 88), and ET + PP + RP (n = 37). The lesions of ET or PP were mainly treated with noninvasive devices (Intense pulsed light, IPL; Dye pulse light, DPL; Dual wavelength laser system, DW) and those of RP were treated with the Fractional carbon dioxide (FCO2) laser. For the mixed subtypes, the general disposal orders of lesions were ET, PP, and later RP, and the fundamental orders of devices application were IPL, DPL, DW, and FCO2 laser. For all types of rosacea except for RP (2–4 sessions), most of the patients received 4–6 sessions of treatments. Of all subtypes of ET, PP, RP, ET + PP, ET + RP, PP + RP, and ET + PP + RP, the patients who achieved more than 50% improvement accounted for 74.5%, 58.3%, 83.3%, 69.2%, 73.3%, 61.4%, and 51.4%, respectively. Conclusion: The multiple, sequential light/laser devices can be safely used in nasal rosacea with various degrees efficacies based on different types. [ABSTRACT FROM AUTHOR]

Er[sup 3+] doped Nb[sub 2]O[sub 5]-TeO[sub 2] (NT) glass suitable for developing optical fiber laser and amplifier has been fabricated and characterized. Intense and broad 1.53 µm infrared fluorescence and visible upconversion luminescence were observed under 975 nm diode laser and 798 nm laser excitation. For 1.53 µm emission band, the full width at half-maximum is 51 nm, the fluorescence lifetime is 2.6 ms, and the quantum efficiency is ∼100%. The maximum emission cross section is 8.52 × 10[sup -21] cm² at 1.532 µm, and is higher than the values in silicon and phosphate glasses. Under 798 nm excitation, efficient 531, 553, and 670 nm upconversion emissions are due to two-photon absorption processes. The "standardized" efficiency for the green upconversion light is 9.5 × 10[sup -4], and this value is comparable to that reported for Er[sup 3+]/Yb[sup 3+] codoped fluoride glasses. Intense visible upconversion fluorescence in Er[sup 3+] doped NT glass can be used in color display, undersea communication, and infrared sensor. [ABSTRACT FROM AUTHOR]

We report on the generation of 7.6 ns, $162~\mu \text{J}$ and 21.3 kW (peak power) single-frequency optical pulses at 780 nm with near-diffraction limited beam quality (M2 < 1.1) from a frequency-doubled all-fiber MOPA system for a 87 Rb based dating application. Frequency doubling is performed in 4-cm long non-critically-phase-matched (NCPM) LBO crystal with a measured conversion efficiency of ~50%. The same technology has also been used to build another similar pulsed laser at 776nm. To the best of our knowledge, this is the highest pulse energy and peak power in a single-frequency laser near 780nm with near-Gaussian beam quality obtained from a frequency-doubled all-fiber MOPA system. The use of the all-fiber MOPA configuration allowed us to develop compact and rugged laser systems at both 780nm and 776nm for 87Rb dating applications. [ABSTRACT FROM AUTHOR]

Background: Associations between vitiligo and thyroid disorders have been suggested, However, the prevalence of thyroid disorders in vitiligo vary widely. Purpose: To conduct a systematic review and meta-analysis assessing the prevalence of thyroid disorders in patients with vitiligo. Method: The PubMed, Cochrane Library, EMBASE, CNKI (China National Knowledge Infrastructure), Chongqing VIP database, and Wanfang database from inception to August 2, 2018 were systematically searched. The pooled prevalence and its 95% confidence interval (CI) were calculated. Results: A total of 77 eligible studies were identified and included, published from 1968 to 2018. Six thyroid disorders including subclinical hyperthyroidism, overt hyperthyroidism, subclinical hypothyroidism, overt hypothyroidism, Graves disease, and Hashimoto thyroiditis were described. The numbers of relative studies were 54 in overt hypothyroidism, 50 in overt hyperthyroidism, 25 in subclinical hypothyroidism, 19 in Hashimoto thyroiditis, 16 in Graves disease, and 10 in subclinical hyperthyroidism. The highest prevalence was 0.06 (95% CI: 0.04–0.07) in subclinical hypothyroidism, and the lowest was 0.01 in subclinical hyperthyroidism (95% CI: 0.00–0.01) or Graves disease (95% CI: 0.01–0.02). Conclusion: Six thyroid disorders showed various prevalence in vitiligo. The highest prevalence was in subclinical hypothyroidism, and the lowest was in subclinical hyperthyroidism or Graves disease. Screening vitiligo patients for thyroid disorders seem plausible, in an effort to detect potential thyroid diseases or to assess the risk of future onset. [ABSTRACT FROM AUTHOR]

This paper reviews the progress made on Nd3+, Er3+, and Yb3+ doped laser glasses at SIOM, China. Key properties of Nd: phosphate and Nd: fluorophosphate ( FP) laser glasses are presented and compared with the commercial laser glasses from Hoya and Schott. Also reviewed are properties of four types of Er: phosphate glasses. The development of a continuous, large-scale melting platform producing high-quality Nd: phosphate laser glass at SIOM is briefly described. Our study on the Stark splitting of Yb3+: 2F7/2 level indicates that mixed-glass formers can significantly improve the Stark splitting, resulting enhancement of lasing performance of Yb: phosphate glass. [ABSTRACT FROM AUTHOR]

Objective: To conduct a meta-analysis assessing the prevalence of vitiligo. Methods: Literatures that reported prevalence rates of vitiligo were identified using EMBASE, PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang database and Weipu database for the period from inception to May 2016. We performed stratified analyses on possible sources of bias, including areas difference, years of publication, gender and age. Publication bias was assessed with Egger’s test method. Results: A total of 103 studies were eligible for inclusion. The pooled prevalence of vitiligo from 82 population- or community-based studies was 0.2% (95%CI: 0.1%–0.2%) and from 22 hospital-based studies was 1.8% (95%CI: 1.4%–2.1%). A relatively high prevalence of vitiligo was found in Africa area and in female patients. For population- or community-based studies, the prevalence has maintained at a low level in recent 20 years and it has increased with age gradually. For hospital-based studies, the prevalence has showed a decreased trend from 60s till now or from young to old. No significant publication bias existed in hospital-based studies (t = 0.47, P = 0.643), while a significant publication bias existed in population- or community-based studies (t = 2.31, P = 0.026). Conclusion: A relatively high prevalence of vitiligo was found in Africa area and in female patients. The prevalence has maintained at a low level in recent years. It showed an inverse trend with age increment in population- or community-based studies and hospital-based studies. [ABSTRACT FROM AUTHOR]

Topical calcipotriol/betamethasone dipropionate ointment/gel has been commonly used for the treatment of psoriasis vulgaris. However, the efficacy of this combination needs to be consolidated. We aimed to assess the effects and safety profile of calcipotriol/betamethasone dipropionate for the treatment of psoriasis vulgaris, using evidence based approach. Randomized controlled trials on the treatment of psoriasis vulgaris with calcipotriol/betamethasone dipropionate were identified by searching PubMed, China National Knowledge Infrastructure and the Cochrane Library. The primary outcome measure was the Psoriasis Area and Severity Index (PASI) score. Ten randomized controlled trials involving 6590 participants were included. The methodologies of the studies were generally of moderate to high quality. These trials used topical calcipotriol/betamethasone dipropionate for 4 or 8 weeks, and were compared with topical calcipotriol or betamethasone. The results showed that calcipotriol/betamethasone dipropionate was more effective than controls. A four-week treatment with calcipotriol/betamethasone dipropionate did not show any significant difference between the once-daily or twice-daily regimen. The adverse events of calcipotriol/betamethasone dipropionate were tolerable and acceptable. The reports included in this review are heterogenous and have limitations. Topical application of calcipotriol/betamethasone dipropionate once daily is an efficacious treatment for psoriasis vulgaris and is associated with few side effects. [ABSTRACT FROM AUTHOR]

A Tm:germanate fiber laser produced >0.25 mJ/ pulse in a 45 ns pulse. It is capable of producing multiple Q-switched pulses from a single pump pulse. With the addition of a diffraction grating, Tm:germanate fiber lasers produced a wide, but length dependent, tuning range. By selecting the fiber length, the tuning range extends from 1.88 to 2.04 μm. These traits make Tm:germanate lasers suitable for remote sensing of water vapor. [ABSTRACT FROM AUTHOR]

Er 3+ doped Na2O–Nb2O5–TeO2 (NNT) glasses suitable for making optical waveguide devices has been fabricated and characterized. Intense 1.53 μm infrared fluorescence and green upconversion luminescence were observed under 975 nm diode laser and 798 nm laser excitation. The optical absorption, the Judd–Ofelt parameters and the spontaneous transition probabilities have been measured and calculated. The quantum efficiency of 1.53 μm emission band is proved to be ~100%. The maximum emission cross-section is 1.02×10-20 cm2 at 1.533 μm, and it is more than 30% higher than the values in silicate and phosphate glasses. Under 798 nm excitation, strong green and weak red upconversion luminescence was observed at room temperature. The 546 nm green band shows a broad full-width at half-maximum of 16 nm. Intense and broad green upconversion fluorescence in Er 3+ doped NNT glass can be used in colour display, undersea communication and infrared sensor. High concentration of Na2O is a benefit to developing waveguide device from the glass. [ABSTRACT FROM AUTHOR]