Functional polymeric films with antireflective and hydrophobic properties have been widely used for electronic device displays. However, the design of such functional films with an antimicrobial characteristic has been a challenge. We designed a nanostructured surface using a rigorous coupled-wave analysis to obtain a period of 300 nm and an aspect ratio of 3.0 on a flat poly(methyl methacrylate) film. The fabricated nanostructure was hydrophobic and exhibited the desired optical characteristics with a reflectance of less than 0.5% over the visible wavelength range. Furthermore, the nanoimprinted polymer film exhibited antimicrobial characteristics and low adhesion when compared with the corresponding flat surface. The results suggest that the nanostructured surface designed in this study is multifunctional and should be suitable for the production of protective optical and hygienic polymer films for the displays of portable electronic devices.

Tomato yellow leaf curl virus (TYLCV) is one of the most well-known tomato-infecting begomoviruses and transmitted by Bemisia tabaci. Seed transmission has previously been reported for some RNA viruses, but TYLCV has not previously been described as a seed-borne virus. In 2013 and 2014, without whitefly-mediated transmission, TYLCV was detected in young tomato plants germinated from fallen fruits produced from TYLCV-infected tomato plants in the previous cultivation season. In addition, TYLCV-Israel (TYLCV-IL) was also detected in seeds and their seedlings of TYLCV-infected tomato plants that were infected by both viruliferous whitefly-mediated transmission and agro-inoculation. The seed infectivity was 20–100%, respectively, and the average transmission rate to seedlings was also 84.62% and 80.77%, respectively. TYLCV-tolerant tomatoes also produced TYLCV-infected seeds, but the amount of viral genome was less than seen in TYLCV-susceptible tomato plants. When tomato plants germinated from TYLCV-infected seeds, non-viruliferous whiteflies and healthy tomato plants were placed in an insect cage together, TYLCV was detected from whiteflies as well as receiver tomato plants six weeks later. Taken together, TYLCV-IL can be transmitted via seeds, and tomato plants germinated from TYLCV-infected seeds can be an inoculum source of TYLCV. This is the first report about TYLCV seed transmission in tomato.

Unambiguous simultaneous measurement of strain and temperature based on dual long-period fiber gratings by controlling their thermal and strain sensitivities is proposed and experimentally demonstrated. The difference in the wavelength peak shift and the separation with the variation of strain and temperature allows discrimination between the strain and temperature effects, respectively.

In this study, we develop an ultra-fast fiber Bragg grating sensor system that is based on the Fourier domain mode-locked (FDML) swept laser. A FDML wavelength swept laser has many advantages compared to the conventional wavelength swept laser source, such as high-speed interrogation, narrow spectral sensitivity, and high phase stability. The newly developed FDML wavelength swept laser shows a superior performance of a high scan rate of 31.3 kHz and a broad scan range of over 70 nm simultaneously. The performance of the grating sensor interrogating system using a FDML wavelength swept laser is characterized in both static and dynamic strain responses.

In recent years, many methods have been investigated to improve imaging speed in photoacoustic microscopy (PAM). These methods mainly focused upon three critical factors contributing to fast PAM: laser pulse repetition rate, scanning speed, and computing power of the microprocessors. A high laser repetition rate is fundamentally the most crucial factor to increase the PAM speed. In this paper, we review methods adopted for fast PAM systems in detail, specifically with respect to light sources. To the best of our knowledge, ours is the first review article analyzing the fundamental requirements for developing high-speed PAM and their limitations from the perspective of light sources.

Intravascular photoacoustic imaging at 1.7 lm spectral band has shown promising capabilities for lipid-rich vulnerable atherosclerotic plaque detection. In this work, we report a high speed catheterbased integrated intravascular photoacoustic/intravascular ultrasound (IVPA/IVUS) imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A lipid-mimicking phantom and atherosclerotic rabbit abdominal aorta were imaged at 1 frame per second, which is two orders of magnitude faster than previously reported in IVPA imaging with the same wavelength. Clear photoacoustic signals by the absorption of lipid rich deposition demonstrated the ability of the system for high speed vulnerable atherosclerotic plaques detection. V C 2015 AIP Publishing LLC.[http://dx.doi.org/10.1063/1.4929584] Acute cardiovascular events are mostly due to blood clots or thrombus induced by the sudden rupture of vulnerable atherosclerotic plaques within the coronary artery wall. 1,2Thin-cap fibroatheroma (TCFA) has a large, lipid-rich, necrotic core, which has been demonstrated as a primary type of vulnerable atherosclerotic plaque with a high risk to ruptures.3-5 Accurate quantification of both the morphology and composition of a plaque are essential for early detection and optimal treatment in clinics. Several catheter-based intravascular imaging techniques have been investigated. Intravascular ultrasound (IVUS) has been widely used in clinics 4-6 and provides structural information of the atherosclerotic plaque with good penetration depth and axial resolutions of approximately 70 lm. However, the contrast between the lipid-rich region and other soft tissues is limited.6-8 Optical coherence tomography (OCT) has a higher axial resolution of $10 lm, which is ideal for thin fibrous cap thickness measurements, but the penetration depth is less than 2 mm and generally requires blood to be flushed from the imaging area.9,10 Intravascular near-infrared reflection spectroscopy (NIRS) identifies the presence of lipid-rich plaque by detection of the reflection spectrum of the vascular wall, but lacks depth resolution. 11,12Photoacoustic (PA) imaging is a hybrid imaging technique that detects the ultrasound signals generated by the absorption of short pulsed laser inside tissue.13-15 Based on the optical absorption contrast of the tissues within the vessel wall, intravascular photoacoustic (IVPA) imaging for characterizing plaque compositions has been studied. [16][17][18][19][20][21][22][23][24][25][26][27] Recently, due to the high optical absorption by first overtone of C-H bonds around 1720 nm, IVPA imaging of lipid-rich atherosclerotic plaque at 1.7 lm spectral band has been attracting great attention. 21,28 However, current IVPA imaging speed is limited by the repetition rate of commercial nanosecond lasers at 1.7 lm. Using a laser with 10 Hz repetition rate, one cross-sectional image requires tens of seconds to finish, which limits the translation of the technology for in vivo application. 16,18,21,23,24 In this letter, we report o...

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A multiwavelength switching laser is demonstrated by a precise and fast tuning of a composite Lyot-Sagnac comb filter based on multisegment polarization-maintaining fibers. Broadband multiwavelength output is generated by cascaded Raman Stokes waves between 1.12 and 1.58 microns in a fiber-ring cavity with a wave-division-multiplexed coupler. Theoretical and experimental analysis of stable multiwavelength output operation for various Raman gain fibers and the electro-optic switching and flexible space tuning of interleaved wavebands are performed.