The ageing population faces today an increase of chronic diseases such as rheumatism/arthritis, cancer and cardio vascular diseases for which appropriate treatments based on a diagnosis at an early-stage of the disease are required. Some imaging techniques are already available in order to get structural information. Within the non-invasive group, ultrasound (US) images are common in these fields of medicine. However, there is a need for a point-of-care device for imaging smaller structures such as blood vessels that cannot be observed with purely ultrasound based devices. Photoacoustics proved to be an attractive candidate. This novel imaging technique combines pulsed laser light for excitation of tissues and an US transducer as a receptor. Up to now laser sources for existing photoacoustic systems were mainly Nd:YAG lasers or optical parametric oscillators (OPO). In that context, QUANTEL is about to take up the challenge of drastically shrinking the size of these expensive and bulky nanosecond lasers by demonstrating ultra-short pulse emission (30 - 100 ns) with highly efficient laser diodes (LD) in the near-infrared range. Such a laser source is the key for the introduction of photoacoustic technology for point-of-care testing. It will be demonstrated that a laser source as small as a hand, including an innovative LD and its patented driver board, can be integrated into high sensitivity photoacoustic systems. Thanks to highly performant diode bars, emission of 1 mJ was achieved from an emitting surface that can be as small as 5 mm x 1 mm, which could even allow to couple into an optical fiber with simple optical elements. Besides, several wavelengths between 805 and 980 nm can be generated from a single LD, then allowing to adjust the wavelength according to targeted tissue components (blood, fat…). This state-of-the-art laser source presents an outstanding electrical-to-optical efficiency of about 30 %; which enables operation without cooling up to 2 W average power.

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http://spie.org/EPE/conferencedetails/biophotonics-photonic-solutions#2227107