A laser device (10) for ablating a biological tissue (1), comprising: a) a laser source (7) that is configured to emit a laser beam (4) b) optics (8a, 8b, 8x) configured to modify the laser beam (4) such as to direct the laser beam (4) on the biological tissue (1) d) a controller (11) that is configured to control the laser source (7) to emit the laser beam (4) to create an ablation in biological tissue (1), whereby e) a sensor (19) being configured to receive back scattered light from the biological tissue (1) f) a tissue controller (18) that is operationally coupled to the sensor (19) to receive a sensor signal (Ri) of the sensor (19) and g) the tissue controller (18) being configured to compare a series of at least two consecutive sensor signals (R1, R2, R3, . . . ) and being configured to generate a tissue control signal (TCS) when the value of the series of consecutive sensor signals (R1, R2, R3, . . . ) decreases in a predetermined amount.
