Possibility of Pumping Lasers on Alexandrite and Ti:Sapphire Leds Emitting in the Range of 440–510 nm

The energy and spectral characteristics of the most powerful AlInGaN LEDs with emission spectrum peaks at wavelengths of 440, 470, and 510 nm were studied in relation to the pumping of two laser media: Ti:Sapphire (Ti:Al₂O₃) and alexandrite (Cr:Al₂BeO₄). The absorption coefficients of the LED radiation in the laser media were studied experimentally with respect to the peak wavelength, operating mode, and excitation level. The corresponding spectral matching values (the efficiency of absorption of the pump radiation) were calculated for various combinations of the LEDs and active laser media. The energy characteristics (radiation power, pulse energy) of the LED emitters were studied over a wide range of excitation levels. The maximum energy capabilities of the LED emitters were assessed in terms of both output optical power and efficiency. The optimum combinations of LEDs and active laser media to achieve laser generation were determined.