High-power Coherent Light Source Research Articles

Image visualization of photon counting confocal microscopy using statistical estimation

In this paper, we propose image visualization method of photon counting confocal microscopy using statistical estimation. Since high power coherent light source is used to record sectional images from micro-objects in conventional confocal microscopy, it may cause damage for a structure of micro-objects. Thus, low power coherent light source may be required. However, in low light level environment, it is difficult to capture sectional images of micro-objects. On the other hand, photon counting imaging technique can detect sectional images of micro-objects in photon-starved conditions. Therefore, in this paper, we apply a photon counting imaging technique to conventional confocal microscopy for visualization of micro-objects. Photon counting detection can be modeled by statistical process. To visualize micro-objects under photon-starved conditions, statistical estimation methods such as maximum likelihood estimation can be used. In addition, we present color photon counting imaging system which considers different carried photon energy with each basic color channels. To prove and evaluate our method, we show simulation results for image visualization of photon counting confocal microscopy and calculate mean square error.

Fabrication and characterization of linear diffusers based on concave micro lens arrays

We present a new approach of beam homogenizing elements based on a statistical array of concave cylindrical microlens arrays. Those elements are used to diffuse light in only one direction and can be employed together with fly's eye condensers to generate a uniform flat top line for high power coherent light sources. Conception, fabrication and characterization for such 1D diffusers are presented in this paper.

STUDY OF COMPTON BACKSCATTERING BETWEEN RELATIVISTIC ELECTRON BEAM AND SASE LIGHT

Study of Compton backscattering with relativistic high-intense electron beam and single-pass free electron laser (FEL) is carried out to produce high-brightness short X-ray pulse. The single-pass FEL such as SASE is high power coherent light source and the wavelength of the FEL can be tuned changing magnetic field strength of wiggler or undulator continuously. In our study, the relativistic electron beam is generated using a linear accelerator, which is a driver for the FEL. The electron beam is used for both the Compton backscattering and the generation of SASE light. The preliminary experiment of X-ray generation based on Compton backscattering with high-intensity electron beam and infrared SASE light is planed using the L-band linear accelerator at the Institute of Scientific and Industrial Research (ISIR), Osaka University. We will describe the preliminary experiment and the result of numerical studies.