Storage and Retrieval of a Squeezed Vacuum

Storage and retrieval of a squeezed vacuum was successfully demonstrated using electromagnetically induced transparency. 930ns of the squeezed vacuum pulse was incident on the laser cooled 87Rb atoms with an intense control light in a coherent state. When the squeezed vacuum pulse was slowed and spatially compressed in the cold atoms, the control light was switched off. After 3us of storage, the control light was switched on again and the squeezed vacuum was retrieved, as was confirmed using the time-domain homodyne method.Comment: 4 pages, 4 figures, to appear in Physical Review Letter

Spectral Line-by-Line Pulse Shaping of an On-Chip Microresonator Frequency Comb

We report, for the first time to the best of our knowledge, spectral phase characterization and line-by-line pulse shaping of an optical frequency comb generated by nonlinear wave mixing in a microring resonator. Through programmable pulse shaping the comb is compressed into a train of near-transform-limited pulses of \approx 300 fs duration (intensity full width half maximum) at 595 GHz repetition rate. An additional, simple example of optical arbitrary waveform generation is presented. The ability to characterize and then stably compress the frequency comb provides new data on the stability of the spectral phase and suggests that random relative frequency shifts due to uncorrelated variations of frequency dependent phase are at or below the 100 microHertz level.Comment: 18 pages, 4 figure

Single Shot Amplitude and Phase Characterization of Optical Arbitrary Waveforms

Using a time-gated dual quadrature spectral interferometry technique, for the first time we demonstrate single-shot characterization of both spectral amplitude and phase of ~1THz bandwidth optical arbitrary waveforms generated from a 10 GHz frequency comb. Our measurements provide a temporal resolution of 1ps over a record length of 100ps. Singleshot characterization becomes particularly relevant when waveform synthesis operations are updated at the repetition rate of the comb allowing creation of potentially infinite record length waveforms. We first demonstrate unambiguous single shot retrieval using rapidly updating waveforms. We then perform additional single-shot measurements of static user-defined waveforms generated via line-by-line pulse shaping.Comment: 10 pages, 6 figures. Added new references and minor changes to tex

The Advantages and Limitations of a Wearable Active Camera/Laser in Remote Collaboration

The Wearable Active Camera/Laser (WACL) allows the remote experts not only to set their viewpoints into the wearers’ working place independent of their motion but also to point to real objects directly with the laser spot by controlling it through wireless network. In this paper, we examined how communication patterns differ between the WACL interface and a typical headset interface. The results have implications for improving the WACL interface so as to redress the communication asymmetries by enhancing the visual assist

Remote Collaboration using a Shoulder-Worn Active Camera/Laser

The Wearable Active Camera/Laser (WACL) allows the remote collaborators not only to set their viewpoints into the wearer’s workplace independent of the wearer’s motion but also to point to real objects directly with the laser spot. In this paper, we report an user test to examine the advantages and limitations of the WACL interface in remote collaboration by comparing a head-mounted display and a headmounted camera-based headset interface. Results show that the WACL gives better impressions on comfortability when wearing, eye-friendliness, and fatigue in spite of no significant difference in task completion time. We first review related works and user studies with wearable collaborative systems, and then describe the details on the user test

Text Scanner with text detection technology on image sequences

We propose a text scanner, which detects wide text strings in a sequence of scene images. For scene text detection, we use a multiple-CAMShift algorithm on a text probability image produced by a multi-layer perceptron. To provide enhanced resolution of the extracted text images, we perform the text detection process after generating a mosaic image in a fast and robust image registration method. ?? 2002 IEEE