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This paper describes a mass-sensitive microfabricated preconcentrator for use in chemical detection microsystems. The device combines mass sensing and preconcentration to create a smart preconcentrator (SPC) that determines when it has collected sufficient analyte for analysis by a downstream chemical microsystem. The SPC is constructed from a(More)
We have previously demonstrated record modulation bandwidths for oxide-confined vertical cavity surface emitting lasers (VCSELs) based on strained InGaAs-GaAs quantum wells. The monolithic oxide-confined structure provides good optical confinement, low thresholds, efficient operation, and acceptable thermal resistance; these qualities promote high speed(More)
Vertical cavity surface emitting lasers (VCSEL) are expected to achieve large modulation bandwidths at low drive currents, resulting from their small active volume. However, the high speed performance is currently limited by the parasitic capacitance and resistance of these devices. The small signal modulation and large signal dynamic characteristics are(More)
The first monolithic photonic integrated circuit for all-optical generation of millimeter (mm)-wave electrical signals is reported. The design integrates a mode-locked semiconductor ring diode laser, an optical amplifier, and a high-speed photodetector into a single optical integrated circuit. Signal generation is demonstrated at frequencies of 30, 60, and(More)
  • V. Hietala
  • 1999 IEEE MTT-S International Microwave Symposium…
  • 1999
A novel custom high-speed test chip and data reduction technique that allows for the accurate determination of the two-port S-parameters of a passive network from a set of one-port measurements is presented. A typical application for this technique is high-speed integrated circuit package characterization where one-port is of a microelectronic size scale(More)
Surface acoustic wave (SAW) sensors, which are sensitive to a variety of surface changes, have been widely used for chemical and physical sensing. The ability to control or compensate for the many surface forces has been instrumental in collecting valid data. In cases in which it is not possible to neglect certain effects, such as frequency drift with(More)
Flux-flow-based devices such as the superconducting flux flow transistor and magnetically controlled long junctions have been made from thin films of TlCaBaCuO and YBaCuO. The devices are based on the magnetic control of flux flow in their respective structures: a long junction or an array of weak links. The equivalent circuits of the two devices are(More)
A thermal switch has been developed that provides good isolation and insertion loss with adequate switching times to allow a monolithic approach to the switched lines and filter banks. Filter banks in the 8-11-GHz range have been demonstrated with insertion losses of < 1 dB and out-of-band rejection greater than a package-limited 50 dB. Switched delay lines(More)
Vertical Cavity Surface Emitting Lasers (VCSELs) offer many benefits over conventional edge-emitting lasers including economical microelectronic batch processing, easy extension to 2-D arrays, and of interest here, very large intrinsic bandwidths due to reduced cavity volume. Results of electrical characterization of a 19 GHz bandwidth 850 nm VCSEL are(More)
The authors report the fabrication of long, step-edge junctions using TlCaBaCuO with associated control lines that demonstrate strong modulation of critical current, usable current gains, large power gains, and fairly large bandwidths. The devices are operational at up to 95 K and RF measurements have been made at 77 K at frequencies up to a probe-limited(More)