Special Issue "Photodetectors and Imaging Technologies"

Submission

Type of Paper: Review
Title: Ge-photodetectors for Si-based Optoelectronic Integration
Author: Sungjoo Lee
Affiliation: Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive3, 117576, Singapore; E-Mail: elelsj@nus.edu.sg
Abstract: High speed photodetector is one of the key building blocks and allow a large wavelength range of detection from 850nm to telecommunication standards at optical fiber band passes at 1.3 ~ 1.55um. Such devices are key components in several applications like local area networks, board to board, chip to chip and intra chip interconnects. Recent technological achievements on growth of high quality SiGe/Ge films on Si wafers have opened up the possibility of low cost Ge-based photodetectors for near infrared communication bands and high resolution spectral imaging with high quantum efficiencies. In this review article, the recent progresses in the development and integration of Ge-photodetectors on Si-based photonics will be comprehensively reviewed, along with remaining technological issues to be overcome and the future research trend.

Type of Paper: Review
Title: Novel Ultra-sensitive Detectors in the Wavelength Range of 5-50μm
Author: Takeji Ueda
Affiliation: Department of Basic Science, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan; E-Mail: ueda@iis.u-tokyo.ac.jp
Abstract: We developed novel single-photon detectors in the wavelength region of 5-50 μm. The detectors are charge-sensitive infrared phototransistors (CSIPs) fabricated in a GaAs/AlGaAs double quantum well (QW) structure, in which a photo-generated hole (+e) in the floating gate (upper QW) modulates the capacitively-coupled conductance of the underneath channel (lower QW). The excellent noise equivalent power (NEP=8.3x10^(-19) W/Hz^(1/2)) and specific detectivity (D*=8x10^14cmHz^(1/2)/W) are demonstrated for 14.7 micron detection up to 23K, which are by a few orders of magnitude better than those of the state-of-the-art values of other detectors. The dynamic range exceeds 10⁶ (~aW to pW) by repeatedly resetting the accumulated holes in the upper QW. The simple structure is feasible for detector array fabrication and will make it possible to monolithically integrate with reading circuit.

Type of Paper: Article
Title: Characterization of Phycobiliprotein Accumulation and Morphology by Confocal Laser Scanning Microscopy of Live Fremyella diplosiphon Cells
Author: Beronda Montgomery
Affiliation: MSU-DOE Plant Research Laboratory, Department of Biochemistry and Molecular Biology, Michigan State University, 322 Plant Biology Building, East Lansing, MI 48824-1312, USA; E-Mail: montg133@msu.edu
Abstract: Fremyella diplosiphon is a freshwater, filamentous cyanobacterium that exhibits light-dependent regulation of photosynthetic pigment accumulation and cellular and filament morphologies in a well-known process complementary chromatic adaptation (CCA). One of the techniques that we use to investigate the molecular bases of distinct aspects of CCA is confocal laser scanning microscopy (CLSM) that capitalizes on the autofluorescent properties of phycobiliproteins. We employed CLSM to perform spectral scanning analyses of F. diplosiphon strains grown under distinct light conditions. We report optimized utilization of CLSM to elucidate the molecular basis of the photoregulation of pigment accumulation and morphological responses in F. diplosiphon.

Title: Position Sensitive Gaseous Photodetectors
Authors: E. Nappi ¹, V. Peskov ^2,3
Affiliations: ¹ INFN, Bari, Italy
² CERN, Geneva, Switzerland; E-Mail: Vladimir.Peskov@cern.ch
³ UNAM, Mexico
Abstract: Advances in the technologies associated with position sensitive gaseous detectors featuring CsI as reflective photoconverters will be reviewed. These photodetectors represent the most effective solution for what concerns cost and performance in the case of large area Cherenkov imaging applications in relatively low rate (or low occupancy) high energy physics and astrophysics experiments. Moreover, they are the only choice when the Cherenkov detector is embedded in a magnetic field. Recently proposed single-photon MPGDs (Micro-Pattern-Gaseous Detectors) will be also discussed in view of the successful efforts so far made to extend their sensitivity to visible light. With some modifications, photosensitive gaseous detectors can also be used in the imaging of X-rays and particles.