Red Pitaya becomes even more versatile when custom extension boards are attached to it, hence we show a couple of examples that utilize extension boards below.
Simple Coherent Laser Sensor
The guys atĀ KoheronĀ designed a small laser board which fits on top of the Red Pitaya.
More details can be foundĀ here.
Doppler Lidar Velocimeter
Doppler effect is what we experience when hearing the siren of a moving vehicle: the tone gets higher when the vehicle is approaching and lower when it is driving away.
The frequency of the acoustic wave emitted by the siren is affected by the movement of the vehicle. This effect is not only true for sounds but also for optical waves: when a laser beam with frequency f0Ā is reflected off of a moving target with velocity v, its frequency is shifted for
where c is the speed of light. The factor 2 occurs because the light is not emitted by the target but reflected off of it. In this example the laser emits at a frequency of 193.5 THz (i.e. a wavelength of 1550 nm). A target moving at 1 m/s would shift the laser frequency by 1.29 MHz.
More details can be foundĀ here.