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Laserpoint has developed and is starting market introduction of the fastest commercially available High Speed Laser Energy Sensor (named “Blink HS”, patent pending). The advantage of this sensor over pyroelectric sensors and photodiodes for laser measurement is the combination of fast response time (sub-ns), broadband (0.2 to 11 microns), high energy saturation (10 mJ/pulse), pulse duration from femtosecond to microsecond with frequencies up to 1 MHz. In a custom solution the response of the sensor was reported up to 2 MHz.
The Blink HS Sensor has been fully validated during benchmark test at Fraunhofer-Institute for Solar Energy Systems; the average power lasers emission was inferred by energy/pulse (of every pulse) and frequency detection, in a wide range of power, wavelength, and pulse duration, and is compliant with specified calibration uncertainty.
Here, we focus on two key laser characteristics, i.e. turn on transient effect and pulse to pulse stability of medium power lasers.
Some lasers cannot output pulse trains with constant pulse energies when gated. Especially the first pulse of the pulse train might have a considerably higher energy. Blink HS Sensor allowed us to capture and quantify metrologically the pulses just after the gate signal was turned from low to high.
The pulse to pulse stability is a paramount figure of merit of high-quality lasers, in order to allow precise and reproducible micromachining processes, laser metrology, etc.
Sensor operation in “pulses parameters mode” allows the detection and recording of the energy of 32,768 consecutive pulses, e.g. at 10 kHz a snapshot of 3.28 s emission can be observed.
Peak power, energy/pulse and instantaneous frequency are computed and recorded for each pulse; those data, along with quantization error as low as 0.35 microjoule allows the detailed characterization of high stability laser sources.
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