Four wavelengths: 532 nm, 555 nm, 579 nm, 606 nm; pulse-by-pulse switchable with 2 kHz; Pulse Energy 20 µJ; Pulse Length <5 ns
The diode-pumped solid-state laser TETRA emits very short laser pulses (< 5 ns) of high energy (up to 20 µJ) with four wavelengths in the visible range, which are particularly suitable for multispectral photoacoustic imaging. Using sophisticated technology, the TETRA laser can switch from pulse to pulse between these four wavelengths with a very high pulse repetition frequency of 2 kHz.
Utilizing the Raman effect and the light of a 532 nm pump laser, the TETRA laser additionally generates the wavelengths 555 nm, 579 nm and 606 nm. A tunable optical filter separates the four wavelengths and routes one wavelength at a time to the optical output of the unit at a switching frequency of up to 2 kHz. This makes TETRA about ten times faster than tunable lasers based on OPOs (Optical Parametric Oscillators) – typical frequencies of such OPO systems range from 100 Hz to 200 Hz – while also being considerably more cost-effective.
The wavelengths emitted by TETRA are well matched to the absorption curves of many blood components, making the laser particularly suitable for photoacoustic tomography in biomedicine. We have equipped TETRA with a number of features to meet the requirements of medical safety standards for use in clinical environments. For instance a fast, fault-tolerant shutter at the laser output interrupts the beam in the event of a fault in the shortest possible time in order to avoid any hazards to a patient.