Publications
Ring array antenna with optimized beamformer for simultaneous transmit and receive
Summary
Summary
In order to avoid self-interference, Simultaneous Transmit And Receive (STAR) systems require low mutual coupling between their respective transmit and receive antennas. This paper discusses the development of an 8-element transmit ring array antenna on a circular ground plane with a raised receive element. When combined with a beamformer that...
Measurement of the third-order nonlinear optical susceptibility chi^(3) for the 1002-cm^-1 mode of benzenethiol using coherent anti-Stokes Raman scattering with continuous-wave diode lasers
Summary
Summary
The components of the third-order nonlinear optical susceptibility x^(3) for the 1002-cm^?1 mode of neat benzenethiol have been measured using coherent anti-Stokes Raman scattering with continuous-wave diode pump and Stokes lasers at 785.0 and 852.0 nm, respectively. Values of 2.8±0.3 X 10^-12, 2.0±0.2 X 10^-12, and 0.8±0.1 X 10^-12 cmg^-1...
Sub-picosecond pulses at 100 W average power from a Yb:YLF chirped-pulse amplification system
Summary
Summary
We present a high-repetition-frequency, diode-pumped, and chirped-pulse amplification system operating at 106 W average output with excellent beam quality (M^2 = 1.3), based on cryogenically cooled Yb:YLF. 1 nJ seed pulses, derived from a mode-locked Ti:sapphire laser, are first amplified to 1 mJ pulse energy at 10 kHz repetition frequency...
Dynamical decoupling and dephasing in interacting two-level systems
Summary
Summary
We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's transition frequency relative to the two-level system, we realize a refocusing pulse that reduces dephasing...
Impact of semiconductor optical amplifiers in coherent down-conversion microwave photonic links
Summary
Summary
We compare the impact of conventional semiconductor optical amplifiers (SOAs) and high linearity slab-coupled optical waveguide amplifiers (SCOWAs) on the SFDR of carrier-suppressed coherent down-conversion microwave photonic links.
Waveguide engineering for hybrid Si/III-V lasers and amplifiers
Summary
Summary
Using adiabatic tapers, hybrid silicon / III-V lasers and amplifiers are integrated with conventional thin (t = 0.25 um) silicon waveguides. Amplifiers have ~12 dB intrachip gain, and similar lasers have thresholds of 35 mA.
Rational design and optimization of plasmonic nanoarrays for surface enhanced infrared spectroscopy
Summary
Summary
We present an approach for rational design and optimization of plasmonic arrays for ultrasensitive surface enhanced infrared absorption (SEIRA) spectroscopy of specific protein analytes. Motivated by our previous work that demonstrated sub-attomole detection of surface-bound silk fibroin [Proc. Natl. Acad. Sci. U.S.A. 106, 19227 (2009)], we introduce here a general...
A compressed sensing analog-to-information converter with edge-triggered SAR ADC core
Summary
Summary
This paper presents the design and implementation of an analog-to-information converter (AIC) based on compressed sensing. The core of the AIC is an edge-triggered charge-sharing SAR ADC. Compressed sensing is achieved through random sampling and asynchronous successive approximation conversion using the ADC core. Implemented in 90nm CMOS, the prototype SAR...
Vertically stacked RF switches by wafer-scale three-dimensional integration
Summary
Summary
Vertically stacked RF switches implemented by wafer-scale three-dimensional (3D) integration of three completely fabricated silicon-on-insulator wafers are demonstrated. The individual switch performance was maintained through the 3D integration process while the signal path is shortened by vertical interconnects. The footprint of the switch can be shrunk in proportion to the...
The MIT IAP radar course: build a small radar system capable of sensing range, Doppler, and synthetic aperture (SAR) imaging
Summary
Summary
MIT Lincoln Laboratory sponsored a radar short course at MIT campus during the January 2011 Independent Activities Period (IAP). The objective of this course was to generate student interest in applied electromagnetics, antennas, radio frequency (RF) electronics, analog circuits, and signal processing by building a short-range radar sensor and using...