Peter Haring Bolívar

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We present difference-frequency stabilization of free-running distributed-feedback (DFB) diode lasers, maintaining a stable phase-lock to a local oscillator (LO) signal. The technique has been applied to coherent hybrid THz imaging which employs a high-power electronic radiation source emitting at 0.62 THz and electro-optic detectors. The THz radiation of(More)
We demonstrate the operation of a miniaturized all-electronic CMOS based THz spectrometer with performances comparable to that of a THz-TDS spectrometer in the frequency range 20 to 220 GHz. The use of this all-electronic THz spectrometer for detection of a thin TiO<sub>2</sub> layer and a B. subtilis bacteria film on top of a plasmonic surface is(More)
A label-free sensing approach for the label-free characterization of genetic material with terahertz (THz) electromagnetic waves is presented. Time-resolved THz analysis of polynucleotides demonstrates a strong dependence of the complex refractive index of DNA molecules in the THz frequency range on their hybridization state. By monitoring THz signals one(More)
THz-wave-based approaches for the label-free characterization of genetic material are described. Time-resolved THz spectroscopic analysis of genetic sequences (polynucleotides) demonstrate a distinct complex refractive index in the THz frequency range as a function of the binding state of the analysed DNA sequences. By monitoring THz signals, one can thus(More)
Imaging systems operating in the sub-terahertz frequency range have proven to be highly attractive devices for non-destructive testing applications. Especially frequency modulated system concepts have shown a great potential for volume inspection in industrial process and quality control, but often lack fast image acquisition times. We report on the(More)
Graphene/silicon (G/Si) heterojunction based devices have been demonstrated as high responsivity photodetectors that are potentially compatible with semiconductor technology. Such G/Si Schottky junction diodes are typically in parallel with gated G/silicon dioxide (SiO2)/Si areas, where the graphene is contacted. Here, we utilize scanning photocurrent(More)
We report on uncooled antenna-coupled thermoelements with a fast response time operating at 0.812 THz. Each sensor pixel consists of 8 thermocouples in series. As thermoelectric structure, a BiSb/Sb freestanding air-bridge is used, fabricated by micromachining. A thermal time constant as low as 22 &#x03BC;s and a NEP of 130 pW/Hz<sup>0.5</sup> at 1 kHz(More)
We demonstrate a hybrid system for THz raster scan imaging using frequency-stabilized DFB lasers for electro-optic detection. The system combines a 0.65-THz micro-electronic narrow-band emitter with two synchronized diode lasers, providing two-color laser radiation. The functional principle promises three-dimensional real-time imaging capabilities.
We present a new 2D electrooptical THz detector using a photonic mixing device (PMD) camera. The combination of PMD-cameras with electrooptic THz sensing increases sensitivity drastically, enabling the use of non amplified fs laser sources for high resolution real-time THz electrooptic imaging.
Integrating a thermopile with a low power operational amplifier is an effective and cost-efficient approach to obtain a high performance compact Terahertz power detector. Here we present the development of such an integrated detector, including the fundamental building blocks, the final realization and related characterization. The responsivity and(More)