Horacio Lamela

Prof. Horacio Lamela

Electronic Engineering, University Carlos III of Madrid, Madrid, Spain

Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 June 2009 in Optics Letters
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Journal Article
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DGDaniel Gallego
Daniel Gallego
HLHoracio Lamela
Horacio Lamela
This work describes the results of ultrasonic wideband sensors based on single-mode polymer optical fibers that may be used for biomedical applications. We have compared the ultrasonic sensitivities of two Mach–Zehnder interferometric intrinsic optical fiber sensors. One is based on a single-mode polymethylmethacrylate optical fiber and the second on single-mode silica optical fiber, both operating at 632.8 nm. At a frequency of 1 MHz these sensitivities are 13.1 and 0.85 mrad/kPa, respectively. The ultrasonic phase sensitivity of the polymer optical fiber is more than 12 times larger than that from the fused silica fiber in the 1–5 MHz range.

24 November 2009 in Optics Letters
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Journal Article
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HLHoracio Lamela
Horacio Lamela
DGDaniel Gallego
Daniel Gallego
AOAlexander Oraevsky
Alexander Oraevsky
An interferometric sensor based on nonmetallic silica optical fiber is presented as an ultrasonic wideband transducer for optoacoustic imaging applications. We have characterized the sensitivity of the optical fiber sensor by detecting optoacoustic signals from an optically absorbing object embedded in a tissue-mimicking phantom and have compared the signals recorded with those detected from the same phantom using an array of piezoelectric transducers. The optical fiber sensor was also scanned along the phantom surface in order to reconstruct two-dimensional optoacoustic images of the phantom. These images have been compared with images obtained using the Laser Optoacoustic Imaging System, LOIS-64B, demonstrating the feasibility of our fiber-optic sensor as a wideband ultrasonic transducer.

1 March 2002 in Optics Letters
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Journal Article
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HLHoracio Lamela
Horacio Lamela
BRB. Roycroft
B. Roycroft
PAPablo Acedo
Pablo Acedo
RSR. Santos
R. Santos
GCG. Carpintero
G. Carpintero
Monolithic twin-ridge laterally coupled diode lasers emitting at 1.3 µm are presented that have a small-signal modulation bandwidth beyond the relaxation oscillation frequency of a single ridge. Spectra and spectrally resolved far fields are presented for three bias conditions: only one ridge lasing, both ridges lasing just above threshold, and both ridges lasing at biases well above threshold. In the first two cases the spectrum has single-peaked longitudinal modes, whereas the third cases shows splitting to in-phase and out-of-phase modes. The splitting frequency of the optical spectrum is measured to be 7.7 GHz. Small-signal modulation measurements reveal a strong resonance at 7.7 GHz, demonstrating an effect of lateral mode locking. As a result of this effect, the twin-ridge laser can be made to have a -3‐dB bandwidth beyond that associated with its relaxation oscillation frequency.

7 July 2014 in Journal of Spectroscopy
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Journal Article
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EDEhsan Dadrasnia
Ehsan Dadrasnia
SPSujitha Puthukodan
Sujitha Puthukodan
VTVinod V. K. Thalakkatukalathil
Vinod V. K. Thalakkatukalathil
HLHoracio Lamela
Horacio Lamela
GDGuillaume Ducournau
Guillaume Ducournau
JCJean-Louis Coutaz
Jean-Louis Coutaz
We explore the optical and electrical characteristics of monolayer graphene by using pulsed optoelectronic terahertz time-domain spectroscopy in the frequency range of 325–500 GHz based on fast direct measurements of phase and amplitude. We also show that these parameters can, however, be measured with higher resolution using a free space continuous wave measurement technique associated with a vector network analyzer that offers a good dynamic range. All the scattering parameters (both magnitude and phase) are measured simultaneously. The Nicholson-Ross-Weir method is implemented to extract the monolayer graphene parameters at the aforementioned frequency range.

1 January 1999 in Review of Scientific Instruments
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Journal Article
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JIJ. Irby
J. Irby
RMRichard Murray
Richard Murray
PAPablo Acedo
Pablo Acedo
HLHoracio Lamela
Horacio Lamela
A new tangentially viewing interferometer has been operated on the Alcator C-Mod tokamak. This system uses both the near infrared and visible beams from a continuous wave, diode pumped, frequency doubled Nd:YAG laser to produce the two wavelengths needed for vibration subtraction. A single Bragg cell driven at two harmonically related frequencies provides the basis for a novel heterodyne detection technique. Comparison of the data from the tangentially viewing interferometer and a vertically viewing CO 2 interferometer will be discussed.

10 November 2009 in IEEE Journal of Quantum Electronics
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Journal Article
Closed access
RSRui Santos
Rui Santos
HLHoracio Lamela
Horacio Lamela
The nonlinear and chaotic phenomena in lateral coupled diode lasers have been widely studied theoretically. In this work an experimental analysis of the complex nonlinear and chaotic dynamic regimes experimentally observed in these devices and the mechanisms that produces it is made. This analysis is set by means of the RIN electrical spectrum and of the high resolution Fabry-Perot optical spectrum. A mapping of the nonlinear occurrences in these devices is obtained and a study of the relation between the relaxation oscillation frequency and the lateral locking frequency is achieved.