The laser set-up is shown in Figure 1. Specially designed pairs of double-chirped mirrors [1] compensate for higher-order as well as second-order dispersion, and CaF2 prisms permit dispersion adjustment. A 2.7-mm-thick Ti:sapphire crystal is pumped with about 4 W of cw 532 nm power. After modelocked operation is initiated by translating the prism P1, a steady state output power of about 120 mW ...

Incorporation of planar waveguide technology into a spectroelectrochemical sensor is described. In this sensor design, a potassium ion-exchanged BK7 glass waveguide was over-coated with a thin film of indium tin oxide (ITO) that served as an optically transparent electrode. A chemically selective film was spin-coated on top of the ITO film. The sensor supported five optical modes at 442 nm and ...

A two-step K(+)-Na+ and Ag(+)-Na+ ion-exchange technique is introduced to fabricate single-mode channel waveguides in BK7 glass for the telecom-wavelength region. The dependencies of insertion loss, polarization-dependent loss (PDL), end bending loss of curved waveguides on channel width, diffusion time, and annealing time are investigated. Results show that postannealing is a required process ...

ZnO is an important II-VI semiconductor material for devices with possible applications such as piezoelectric transducers, gas sensors, transparent electronic in solar cell, saw devices. Based on known research, ZnO is the most promising in optoelectronic and optical applications, especially in UV region. An understanding of the optical properties of ZnO thin film on different substrates is als...

Surface plasmon resonance sensor is used to measure the variation of dielectric constant sample, but its sensitivity is limited to surrounding temperature fluctuation. We present a high sensitivity phase-based surface plasmon resonance sensor made by gold nano-cylinder array. This structure is not only to reduce thermal conduction by the non-continuous gold array, but also to enhance surface pl...

A series of waveguides was inscribed in a borosilicate glass (BK7) by an 11 MHz repetition rate femtosecond laser operating with pulse energies from 16 to 30 nJ and focused at various depths within the bulk material. The index modification was measured using a quantitative phase microscopy technique that revealed central index changes ranging from 5 x 10(-3) to 10(-2), leading to waveguides tha...

We present a new finishing process that is capable of locally shaping and polishing optical surfaces of complex shapes. A fluid jet system is used to guide a premixed slurry at pressures less than 6 bars to the optical surface. We used a slurry comprising water and 10% #800 SiC abrasives (21.8 mum) to reduce the surface roughness of a BK7 sample from 350 to 25 nm rms and to vary the shape of a ...

Abstract A comparative study of the evolution diameter and depth ablated craters, while varying systematically both pulse energy spot size is reported. It reveals that surface ablation threshold fluences double-checked by diameter-regression method a multiphoton-absorption-based fit show clear dependence on radius processing laser beam BK7 optical glass surface. Tighter focusing results in rise...

Colletotrichum sublineola is an aggressive fungal pathogen that causes anthracnose in sorghum [Sorghum bicolor (L.) Moench]. The obvious symptoms of anthracnose are leaf blight and stem rot. Sorghum, the fifth most widely grown cereal crop in the world, can be highly susceptible to the disease, most notably in hot and humid environments. In the southeastern United States the acreage of sorghum ...