Highly efficient, low-cost femtosecond Cr(3+):LiCAF laser pumped by single-mode diodes.
We describe efficient continuous-wave (cw) and cw mode-locked operations of a Cr(3+):LiCAF laser, pumped by inexpensive single spatial mode laser diodes. Up to 280 mW of cw output power was obtained with 570 mW of absorbed pump power, with a corresponding slope efficiency […]
Continuous sorting of Brownian particles using coupled photophoresis and asymmetric potential cycling.
Feasible sorters need to function rapidly and permit the input and delivery of particles continuously. Here, we describe a scheme that incorporates (i) restricted spatial input location and (ii) orthogonal sort and movement direction features. Sorting is achieved using an asymmetric […]
Three-core fiber-based shape-sensing application.
By using specially designed three-core fiber, a microstructured light-pattern generator for sensing 3-D shapes has been demonstrated. The square or hexagon grid-interferometric fringe pattern formed by the fiber-optic interferometric grid generator is projected onto an object\’s surface. The deformed grid pattern containing information of the object\’s surface topography is […]
Optical image encryption based on the multiple-parameter fractional Fourier transform.
A novel image encryption algorithm is proposed based on the multiple-parameter fractional Fourier transform, which is a generalized fractional Fourier transform, without the use of phase keys. The image is encrypted simply by performing a multiple-parameter fractional Fourier transform with four keys. Optical […]
Refractive and reflective behavior of polymer prisms used for surface plasmon guidance.
Two-dimensional optics with surface plasmons was realized by the use of topographically structured dielectric polymer coatings. Triangles of polymethylmetacrylate (PMMA) with lateral dimensions of some tens of micrometers on top of a silver layer act as two-dimensional prisms for surface plasmons. […]
Enhancement of band-edge emission induced by defect transition in the composite of ZnO nanorods and CdSe/ZnS quantum dots.
A new and general approach to enhance band-edge emission at the expense of defect emission in a semiconductor nanocomposite is proposed. The underlying mechanism is based on the resonance effect between defect transition and band-to-band […]
Generalized wavefront phase for non-Kolmogorov turbulence.
We introduce the Lévy fractional Brownian field family to model the turbulent wavefront phase. This generalized model allows us to overcome the limitations found in a previous approach [Perez et al., J. Opt. Soc. Am. A 21, 1962 (2004)]. More precisely, our new model provides stationary phase […]
Optimization of multiplexed holographic gratings in PQ-PMMA for spectral-spatial imaging filters.
Holographic gratings formed in thick phenanthrenquinone- (PQ-) doped poly(methyl methacrylate) (PMMA) can be made to have narrowband spectral and spatial transmittance filtering properties. We present the design and performance of angle-multiplexed holographic filters formed in PQ-PMMA at 488 nm and reconstructed with […]
Spectral-purity-enhancing layer for multilayer mirrors.
We demonstrate, both theoretically and experimentally, that special spectral-purity-enhancing multilayer mirror systems can be designed and fabricated to substantially reduce the level of out-of-band radiation expected in an extreme ultraviolet lithographic tool. A first proof of principle of applying such spectral-purity-enhancement layers showed reduced out-of-band reflectance by a […]
Highly sensitive refractometer with a photonic-crystal-fiber long-period grating.
We present highly sensitive refractometers based on a long-period grating in a large-mode-area photonic crystal fiber (PCF). The maximum sensitivity is 1500 nm/refractive index unit at a refractive index of 1.33, to our knowledge the highest reported for any fiber grating. The minimal detectable index […]
