A novel technique for wireless optical communications with lenslet array processor

A novel communication technique is proposed, which utilizes a set of mutually distinguishable optical patterns instead of convergent facula to transmit information. Then the capacity is increased by exploiting the optical spatial bandwidth resources. At last, we experimentally demonstrate the proposed communication technique based on four 8 × 8 spatial pattern signals by using lenslet array processor.

Optical system and lens design for Blu-ray disc optical pick-up

During the design process of Blu-ray disc optical pick-up （BD OPU）, the optical system and the collimator lens design is especially important. This paper designs an optical system and some lenses for＇the BD OPU, including collimator lens, beam shaping lens for laser beam shaping, and cylinder lens for signal detecting. In this OPU, we use a triplet lens to collimate the laser beam. At the same time, we build a series of assembly jigs to make sure that each lens can be put into the OPU basement properly. At last, we get the reading spot image and S-curve photo of OPU, which can be used to read Blu-ray disc （BD）.

Three-dimensional optical data storage using a solid immersion lens to focus a femtosecond laser pulse

A solid immersion lens (SIL) has been applied to the writing and reading of three-dimensional optical data storage in transparent materials. Using a SIL with n=1.516 to focus a 150-fs, 800-nm Tiisapphire laser, the 5-layer reading and writing of data are achieved in fused silica and polyethylene methacrylate at a density of 1.1×10 2 b/cm3. Some advantages of the employment of SIL have been discussed.

Parallel fabrication of silicon concave microlens array by femtosecond laser irradiation and mixed acid etching

A method of multi-beam femtosecond laser irradiation combined with modified HF-HNO3-CH3COOH etching is used for the parallel fabrication of all-silicon piano-concave microlens arrays （MLAs）. The laser beam is split by a diffractive optical element and focused by a lens to drill microholes parallely on silicon. An HF-HNO3-H2SO4-CH3COOH solution is used to expand and polish laser-ablated microholes to form micro- lenses. Compared with the HF-HNO3-CH3COOH solution, the solution with H2SO4 can effectively reduce the etched surface roughness. The morphologies of MLAs at different laser powers and pulse numbers are observed. The image array formed by the silicon microlenses is also demonstrated.

Application of polycapillary x ray lens to eliminate both the effect of x ray source size and scatter of the sample in laboratory tomography

A tomography device based on a conventional laboratory x ray source, polycapillary parallel x ray lens （PPXRL）, and polycapillary collimating x ray lens （PCXRL） is designed. The PPXRL can collect the divergent x ray beam from the source and focus it into a quasi-parallel x ray beam with a divergence of 4.7 rarad. In the center of quasi-parallel x ray beam, there is a plateau region with an average gain in power density of 13.8 and a diameter of 630μm. The contrast of the image can be improved from 28.9% to 56.0% after adding the PCXRL between the sample and the detector.

Microlens arrays prepared via colloidal microsphere templating

A simple and efficient templating method in combination with hot embossing technique is developed for fabricating large-area two-dimensional（2D） microlens arrays（MLAs） with uniform shape.By utilizing a modified microchannel method,a 2D large-area hexagonal close-packed（HCP） array of silica colloidal microspheres is prepared and serves as a template in the following hot embossing treatment to create a polycarbonate（PC） microcavity array.Then,with the obtained PC microcavity structure serving as a mold,a hot embossing process is applied to finally achieve a polymethylmethacrylate（PMMA） MLA.The effect of annealing time during the mold preparation process on the dimensions and shapes of the prepared microlens is investigated.The imaging performances of the prepared PC concave microcavities and PMMA convex microlenses are characterized by carrying out projection experiments.Our method provides a rapid and low cost approach to prepare large-area MLAs.

Demultiplexer based on an off-axis holographic lens with low monochromatic aberrations

A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the recording and reconstruction geometries and collimating the reconstruction wave with a gradient-index lens. A demultiplexer operated in the 1 550-nm band with 5-nm channel spacing and -∞-dB crosstalk is obtained using the scheme. The channel spacing can be decreased to 2 nm by etching the cladding of the output fibers to a smaller size.