Local lifetime engineering in 600V pin diode using mix-mode simulation

This paper reports a detailed analysis of the effect of local lifetime killing (LLK) within the drift region on the reverse recovery (RR) characteristics and on-state performance of 600V Silicon PiN diodes. The paper also discusses the influence of the measurement circuit on the reverse recovery of the high voltage diodes and it proposes a simple and effective mix-mode simulation tool for an accurate assessment of the diode performance in reverse recovery mode. © 2013 IEEE.

Micro-electro-mechanical resonant tilt sensor with 250 nano-radian resolution

This paper reports a high-resolution frequency-output MEMS tilt sensor based on resonant sensing principles. The tilt sensor measures orientation by sensing the component of gravitational acceleration along a specified input axis. A combination of design enhancements enables significantly higher sensitivity for this device as compared to previously reported prototype sensors. The MEMS tilt sensor is calibrated on a manual tilt table over tilt angles ranging over 0-90 degrees with a relatively linear response measured in the range of ±20°(linearity error <2.3%) with a scale factor of approximately 50.06 Hz/degree. The noise-limited resolution of the sensor is found to be approximately 250 nano-radians for an integration time of 0.8 s, which is over an order of magnitude better than previously reported results [1]. © 2013 IEEE.

Superradiant emission from a tapered quantum-dot semiconductor diode emitter

Superradiant emission pulses from a quantum-dot tapered device are generated on demand at repetition rates of up to 5 MHz. The pulses have durations as short as 320 fs at a wavelength of 1270 nm. © 2010 Optical Society of America.

Sub-kHz RF electrical linewidth from a 10GHz passively mode-locked quantum-dot laser diode

A packaged 10GHz monolithic two-section quantum-dot mode-locked laser is presented, with record narrow 500Hz RF electrical linewidth for passive mode-locking. Single sideband noise spectra show 147fs integrated timing jitter over the 4MHz-80MHz frequency range. © 2009 Optical Society of America.

Polarization dependence of double resonant Raman scattering band in bilayer graphene

The polarization dependence of the double resonant Raman scattering (2D) band in bilayer graphene (BLG) is studied as a function of the excitation laser energy. It has been known that the complex shape of the 2D band of BLG can be decomposed into four Lorentzian peaks with different Raman frequency shifts attributable to four individual scattering paths in the energy-momentum space. From our polarization dependence study, however, we reveal that each of the four different peaks is actually doubly degenerate in its scattering channels, i.e., two different scattering paths with similar Raman frequency shifts for each peak. We find theoretically that one of these two paths, ignored for a long time, has a small contribution to their scattering intensities but are critical in understanding their polarization dependences. Because of this, the maximum-to-minimum intensity ratios of the four peaks show a strong dependence on the excitation energy, unlike the case of single-layer graphene (SLG). Our findings thus reveal another interesting aspect of electron-phonon interactions in graphitic systems. © 2014 Elsevier Ltd. All rights reserved.