Dr. Martin O. Berendt Profile

Dr. Martin O. Berendt

at MWTechnologies Lda

SPIE Involvement:

Author

Publications (13)

Proceedings Article | 3 June 2022 Poster + Paper

Analog-to-digital versus time-to-digital conversion for analysis of low signal-to-noise ratio pulsed laser ranging return signal

M. Berendt, L. Ferreira, M. Melo

Proceedings Volume 12110, 121100D (2022) https://doi.org/10.1117/12.2636257

KEYWORDS: Signal to noise ratio, Ranging, Interference (communication), Statistical analysis, Receivers, Pulsed laser operation, Signal detection, LIDAR, Data conversion, Avalanche photodetectors

Read Abstract +

Proceedings Article | 27 April 2020 Presentation

Inductive discharge pulse driver in time gated laser ranging (Conference Presentation)

Martin Berendt, Hugo Barbosa, Job Tomé, Miguel Melo

Proceedings Volume 11410, 114100C (2020) https://doi.org/10.1117/12.2558840

KEYWORDS: Ranging, Pulsed laser operation, Semiconductor lasers, Chemical oxygen iodine lasers, Receivers, Transistors, Laser development, Diodes, Modulation, Optical amplifiers

Read Abstract +

Proceedings Article | 27 April 2020 Presentation

Fast settling PWM laser diode driver (Conference Presentation)

Martin Berendt, Hugo Barbosa, Job Tomé, Miguel Melo

Proceedings Volume 11410, 114100D (2020) https://doi.org/10.1117/12.2558826

KEYWORDS: Semiconductor lasers, Modulation, Continuous wave operation, Microcontrollers, Beam controllers, Feedback control, Clocks, Optical amplifiers, Integrated circuit design, Integrated circuits

Read Abstract +

Proceedings Article | 1 April 2020 Presentation + Paper

Laser diode pulse modulation in sensing and materials processing

Martin Berendt, Hugo Barbosa, Job Tomé, Miguel Melo

Proceedings Volume 11356, 1135617 (2020) https://doi.org/10.1117/12.2555821

KEYWORDS: Modulation, Semiconductor lasers, Microcontrollers, Clocks, Linear filtering, Pulsed laser operation, Materials processing, Analog electronics, Optical filters, Time metrology

Read Abstract +

Proceedings Article | 7 March 2019 Paper

Gain clamping by predictive model pump control in MOPA fiber laser

M. Ole Berendt, H. Barbosa, M. Melo

Proceedings Volume 10897, 108972L (2019) https://doi.org/10.1117/12.2510680

KEYWORDS: Fiber lasers, Optical amplifiers, Pulsed laser operation, Laser systems engineering, Fiber amplifiers, Modulation, Oscillators, Semiconductor lasers, Optical isolators, Analog electronics

Read Abstract +

SPIE Journal Paper | 6 December 2018 Open Access

Ultrafast laser-scanning optical resolution photoacoustic microscopy at up to 2 million A-lines per second

Thomas John Allen, Josh Spurrell, Martin Berendt, Olumide Ogunlade, Shaif Alam, Edward Zhang, David Richardson, Paul Beard

JBO, Vol. 23, Issue 12, 126502, (December 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.12.126502

KEYWORDS: Video, Fiber lasers, Ear, Optical resolution, Photoacoustic microscopy, Imaging systems, Photoacoustic spectroscopy, Fiber optics sensors, Sensors, Laser optics

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 15 March 2018 Presentation

Compact fibre laser system with 15mJ pulse energy for photoacoustic tomography (Conference Presentation)

Thomas Allen, Martin Berendt, Shaif-ul Alam, Nam Huynh, David Richardson, Paul Beard

Proceedings Volume 10494, 104941Z (2018) https://doi.org/10.1117/12.2288820

KEYWORDS: Fiber lasers, Photoacoustic tomography, Tomography, Photoacoustic spectroscopy, Acquisition tracking and pointing, Acoustics, Laser scanners, 3D scanning, Laser tissue interaction, Pulsed laser operation

Read Abstract +

Photoacoustic signals are typically generated using Q-switched Nd:YAG pumped OPO systems, as they can provide the necessary nanosecond pulse durations with mJ pulse energies required for photoacoustic tomography. However, these sources are often bulky, require external water cooling and regular maintenance and provide low pulse repetition frequencies (PRF<100Hz) thus limiting image frame rate. Fibre lasers can overcome these limitations and additionally offer much greater flexibility in their temporal output characteristics (e.g. pulse shaping and duration). Although fibre lasers have been used in optical-resolution photoacoustic microscopy, they have found limited application in widefield photoacoustic tomography (PAT) due to the relatively low pulse energy (<1mJ) provided by commercial systems. These low pulse energies are a consequence of small core diameter (<25m) fibres required to achieve a high beam quality. However, for widefield PAT, high beam quality is not a requirement and therefore fibre lasers with larger core diameters (>100m) can be used, enabling significantly higher pulse energies (>10mJ) to be achieved. A novel compact fibre laser which uses a custom drawn large core diameter fibre (100m) to provide high pulse energies (15mJ) and variable PRFs (100Hz-1kHz) and pulse durations (10-400ns) has been developed and evaluated. The fibre laser was combined with a fast Fabry Perot (FP) scanner in order to evaluate its suitability for PAT of biological tissue. The high PRF (>400Hz) of the laser has allowed tomographic images of the microvasculature of the palm of a hand to be obtained in less than one second, significantly quicker than previously achieved with a FP scanner. In addition, the ability to arbitrarily vary the temporal shape of the laser pulse offers new opportunities for controlling the acoustic frequency content of the photoacoustic signal in order to optimise penetration depth and image resolution. For example, the laser pulse duration can be increased in order to shift the acoustic frequency components to lower frequencies which are less attenuated by tissue acoustic absorption and thus improve SNR. To investigate these concepts, a tissue mimicking phantom was imaged for a range of tailored excitation pulses (e.g. different pulse durations, trains of pulses) and their effect on the contrast to noise ratio (CNR) and image resolution observed. A novel compact fibre laser, able to provide higher pulse energies (>10mJ) than previously reported and with enhanced functionality is presented. It is demonstrated that fibre lasers are a viable alternative to standard Q-switched lasers for photoacoustic tomographic applications in medicine and biology.

Proceedings Article | 17 March 2016 Presentation + Paper

Novel fibre lasers as excitation sources for photoacoustic tomography and microscopy

T. Allen, M. Berendt, J. Spurrell, S. Alam, E. Zhang, D. Richardson, P. Beard

Proceedings Volume 9708, 97080W (2016) https://doi.org/10.1117/12.2211733

KEYWORDS: Fiber lasers, Photoacoustic tomography, Photoacoustic spectroscopy, Imaging systems, Laser development, Acquisition tracking and pointing, Image acquisition, Photoacoustic imaging, Microscopy, Optical resolution

Read Abstract +

Proceedings Article | 26 February 2013 Paper

Destructive random backscattering pulses showing Brillouin signature in MOPA fiber laser systems

M. Melo, M. Berendt, J. Sousa

Proceedings Volume 8601, 86011P (2013) https://doi.org/10.1117/12.2001898

KEYWORDS: Modulation, Fabry–Perot interferometers, Semiconductor lasers, Optical amplifiers, Oscillators, Backscatter, Fiber lasers, Spectrum analysis, Laser systems engineering, Fiber amplifiers

Read Abstract +

Proceedings Article | 11 February 2011 Paper

Stimulated Raman scattering mitigation through amplified spontaneous emission simultaneous seeding on high power double-clad fiber pulse amplifiers

M. Melo, J. Sousa, M. Berendt

Proceedings Volume 7914, 79142N (2011) https://doi.org/10.1117/12.875297

KEYWORDS: Raman spectroscopy, Optical amplifiers, Fiber amplifiers, Raman scattering, High power fiber amplifiers, Fiber lasers, Cladding, Signal attenuation, Modulation, Semiconductor lasers

Read Abstract +

Proceedings Article | 17 February 2010 Paper

20-mW 70-nm bandwidth ASE fibre optic source at 1060-nm wavelength region for optical coherence tomography

Irina Trifanov, Paulo Caldas, Liviu Neagu, Rosa Romero, Martin Berendt, José Salcedo, Adrian Podoleanu, António Lobo Ribeiro

Proceedings Volume 7580, 75800O (2010) https://doi.org/10.1117/12.844905

KEYWORDS: Optical coherence tomography, Imaging systems, Optical filters, Superluminescent sources, Fiber optics, Image resolution, In vivo imaging, Coherence imaging, Ophthalmology, Neodymium

Read Abstract +

Proceedings Article | 30 December 2008 Paper

Development of fibre optic broadband sources at 1 μm region for optical coherence tomography

Irina Trifanov, Martin Berendt, José Salcedo, Adrian Podoleanu, António Lobo Ribeiro

Proceedings Volume 7139, 713906 (2008) https://doi.org/10.1117/12.815347

KEYWORDS: Optical coherence tomography, Optical filters, Ytterbium, Fiber optics, Neodymium, Fiber couplers, Absorption, Superluminescent sources, Wavelength division multiplexing, Semiconductor lasers

Read Abstract +

Proceedings Article | 23 February 2006 Paper

Product design issues relating to rare-earth doped fiber ring lasers and superfluorescence sources

João Sousa, Miguel Melo, Luís Ferreira, José Salcedo, Martin Berendt

Proceedings Volume 6102, 610223 (2006) https://doi.org/10.1117/12.647843

KEYWORDS: Fiber lasers, Optical filters, Mirrors, Resonators, Polarization, Fiber Bragg gratings, Electronic filtering, Temperature metrology, Wavelength division multiplexing, Optical fibers

Read Abstract +

Showing 5 of 13 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years