The key features and performances of a compact, lightweight, high power Er3+:Yb3+ glass laser transmitter are reported on. The theory employed to get an optimal design of the device is also described. In free running regime high energies of about 15mJ in 3ms long pulses were obtained, with an optical efficiency close to
85%. When q-switched by a Co: MALO crystal of carefully selected initial transmittivity, a high peak power in excess of
500 kW was obtained in about 9ns pulse duration, with an optical efficiency of 60%.
The laser was successfully run with no significant power losses at repetition rates up to 5Hz due to a carefully designed
heat sink which allowed an efficient conduction cooling of both the diode bars and the phosphate glass.
The transmitter emits at a wavelength of 1535nm in the
so-called "eyesafe" region of the light spectrum thus being
highly attractive for any application involving the risk of human injury as is typically the case in remote sensing
activities. Moreover, the spectral band around 1,5mm corresponds to a peak in the athmospheric transmittance thus being
more effective in adverse weather conditions with respect to other wavelengths.
Actually, the device has been successfully integrated into a rangefinder system allowing a reliable and precise detection
of small targets at distances up to 20Km. Moreover, the transmitter capabilities were used into a state of the art infrared
laser illuminator for night vision allowing even the recognition of a human being at distances in excess of 5Km.