Project title, ESR5: Multi modal approaches and applications
Aiming to improve combined optical coherence tomography and multispectral photoacoustic microscopy by proving a single supercontinuum source suitable for simultaneous in-vivo imaging
Current projects and research areas
- High power fiber lasers
- Photonics crystal fibers and supercontinuum sources
- Dual modality: photoacoutic microscopy (PAM) and optical coherence tomography (OCT)
- Multispectral PAM
Photoacoutic microscopy (PAM) is based on tissues absorption, using a supercontinuum source is a ultra-broad band (typically 500-2400nm) may be relevant for multispectral PAM and permits to image multiple absorbers within a sample and give the oxygen saturation of the imaged blood vessels for instance. For PAM the supercontinuum source need to be filtered within a relatively small bandwidth (<50nm). However current supercontinuum sources have too low power to be used for multispectral PAM.
I worked at NKT Photonics on building a supercontinuum source with sufficient energy (>50nJ) and bandwidth (<20nm) for multispectral PAM. This single source has already proved its usefulness for multispectral PAM (<2nJ, <15nm) on ex-vivo retinal pigment epithelium and blood samples, and in-vivo PAM on a mouse ear (120nJ, 250nm). This supercontinuum source has been used as well for OCT on in-vivo mouse ears.
Recent developments were focused on making the supercontinuum source robust with sufficient energy for in-vivo combined multispectral PAM and OCT. The dual modality system is currently in the process of being build at the University of Kent.
- December 2014 – December 2017
Early stage Marie Curie researcher (UBAPHODESA, FP7-PEOPLE-2013-ITN, 607627) at NKT Photonics A/S (DK) and University of Kent (UK)
- March 2014 – August 2014
R&D internship in fiber lasers and LIDAR systems at Leosphere (FR)
- June 2013 – August 2013
Sales engineer internship in fiber lasers at Keopsys (DE)
- September 2012 – February 2014
Entrepreneurship education with start-up experience in lasers and nonlinear optics at Aimé Cotton and Charles Fabry Laboratories (FR)
- July 2012
Research internship in nonlinear optics at Charles Fabry Laboratory (FR)
- September 2012 – August 2014
MSc in Laser, Optics and Matter, and Entrepreneurship at Institute of Optics Graduate School ParisTech (FR)
- September 2008 – August 2011
BSc in Math, Physics and Optics at Lycée H. Bergson (FR) and Institute of Optics Graduate School ParisTech (FR)
- June 2008
French Baccalaureat with honors
- M. Bondu, C. Brooks, C. Jakobsen, K. Oakes, P. M. Moselund, L. Leick, O. Bang, and A. Podoleanu, “High energy supercontinuum sources using tapered photonic crystal fibers for multispectral photoacoustic microscopy”, Journal of Biomedical Optics 21 (6), 061005 (2016).
We demonstrated a record bandwidth high energy supercontinuum source suitable for multispectral photoacoustic microscopy. The source has more than 150 nJ∕10 nm bandwidth over a spectral range of 500 to 1600 nm. This performance is achieved using a carefully designed fiber taper with large-core input for improved power handling and small-core output that provides the desired spectral range of the supercontinuum source.
- X. Shu, M. Bondu, B. Dong, A. Podoleanu, L. Leick, and H. F. Zhang, “Single all-fiber-based nanosecond-pulsed supercontinuum source for multispectral photoacoustic microscopy and optical coherence tomography”, Optics Letters Vol. 41, No. 12 (2016).
Abstract:We report the usefulness of a single all-fiber-based supercontinuum (SC) source for combined photoacoustic microscopy (PAM) and optical coherence tomography (OCT). The SC light is generated by a tapered photonic crystal fiber pumped by a nanosecond pulsed master oscillator power amplifier at 1064 nm. The spectrum is split into shorter wavelength band (500–800 nm) for single/multispectral PAM and a longer wavelength band (800–900 nm) band for OCT. In vivo mouse ear imaging was achieved with an integrated dual-modality system. We further demonstrated its potential for spectroscopic photoacoustic imaging by doing multispectral measurements on retinal pigment epithelium and blood samples with 15-nm linewidth.
Conference, workshop and summer school
- M. Bondu, et al., “High energy supercontinuum sources for photoacoustic imaging”, Biophotonics’15 Summer school (June 2015, SE).
- M. Bondu, X. Shu, B. Dong, L. Leick, A. Podoleanu, and H. F. Zhang, “A novel all fiber-based ns supercontinuum source for multispectral photoacoustic microscopy and optical coherence tomography”, Talk, Photonics West, Photons Plus Ultrasound: Imaging and Sensing 2016 (February 2016, USA).
The light source is currently a limiting factor in performing multispectral photoacoustic microscopy. In addition, no source has so far proved its usefulness to achieve multimodal imaging combining simultaneouslt the structural information of optical coherence tomography (OCT) and the functional information of photoacoustic microscopy (PAM). We present here a novel supercontinuum source with 2 ns pulse duration, 25 kHz pulse repetition rate and an enhanced pulse energy of more than 5 nJ/nm covering a broad wavelength range from 500 nm to 2300 nm that allows such multimodal applications. This supercontinuum source is all fiber-based and uses a novel tapered photonics crystal fiber allowing energy in the visible.
In a first experiment, absorption spectra of retinal pigment epithelium and blood obtained with multispectral PAM were reconstructed by using 15 nm bands containing over 1.5 nJ on the sample and scanning them over 500 to 850 nm range. In a second experiment, a multimodal system, integrating PAM and OCT with the single supercontinuum source, was used to image in-vivo mouse ears. The OCT was performed with over 0.3 mW average power on the sample within the 800-900 nm wavelength range, a lateral resolution better than 9 um and an axial resolution of 4.6 um. Visible light with 120 nJ pulse energy was used for the PAM measurement to reconstruct the three dimensional vessel network, yielding images were reconstructed with a lateral resolution better than 5 um and an axial resolution of 51 um.
- M. Bondu, C. Brooks, P. M. Moselund, L. Leick, and A. Podoleanu, “Higher energy supercontinuum source for photoacoustic microscopy”, Poster, Photonics West, Photons Plus Ultrasound: Imaging and Sensing 2016 (February 2016, USA).
No current sources are suitable for fast multispectral photoacoustic microscopy (PAM), as they are either wavelength or energy limited. We report on a new supercontinuum source that achieves pulse energies of more than 100nJ per 10nm bandwidth over a wide wavelength range of 475-2000nm with nanosecond pulses and kHz pulse repetition rates. This is an order of magnitude improvement in energy over current state-of-the-art sources, afforded by the development of an innovative, highly nonlinear fiber design. Multispectral PAM and multimodal imaging utilizing a single source will be realized through further development of supercontinuum sources generated with this fiber design.
- Workshop: Leadership and diversity in organisations, School of Psychology, University of Kent (8 September 2016, UK).