The mechanism research of the Cr^4＋Nd^3＋：YAG laser

The 946nm diode-pump microchip self-Q-switched laser of a chromium and neodymium codoped yttrium aluminum garnet crystal material (Cr^{4+}Nd^{3+}:YAG) is studied, especially about its physical mechanism of operation. The {}^4F_{3/2}→{}^4I_{9/2} transition of Nd^{3+} ion is beneficial to achieving laser oscillation in a quasi-three-level system based on coating the cavity mirrors of the microchip with films that suppress the 1064nm operation and enhance the 946nm laser. The Cr^{4+} ion is a saturable absorber. The initial loss N_{t1} is high, which acts as the threshold for laser oscillation. The stable loss N_{t2} is low because the Cr^{4+} ion is acceleratively bleached by the fast enhancement of the oscillating laser. The high N_{t1}, small N_{t2} and fast progresses permit the oscillating laser of the Cr^{4+}Nd^{3+}:YAG to have a good self-Q-switched property whose full width at half maximum is about 4.2ns. Its highest laser power is about 5.7mW. Its peak power is about 150W. Its good fundamental transverse TEM_{00} mode results from the absorption bleaching established by both the pump and oscillating lasers, which suppress other transverse mode and allow the oscillation only in the fundamental transverse TEM_{00} mode.

The mechanism research of the Cr4+Nd3+:YAG laser

The 946nm diode-pump microchip self-Q-switched laser of a chromium and neodymium codoped yttrium aluminum garnet crystal material (Cr^{4+}Nd^{3+}:YAG) is studied, especially about its physical mechanism of operation. The {}^4F_{3/2}→{}^4I_{9/2} transition of Nd^{3+} ion is beneficial to achieving laser oscillation in a quasi-three-level system based on coating the cavity mirrors of the microchip with films that suppress the 1064nm operation and enhance the 946nm laser. The Cr^{4+} ion is a saturable absorber. The initial loss N_{t1} is high, which acts as the threshold for laser oscillation. The stable loss N_{t2} is low because the Cr^{4+} ion is acceleratively bleached by the fast enhancement of the oscillating laser. The high N_{t1}, small N_{t2} and fast progresses permit the oscillating laser of the Cr^{4+}Nd^{3+}:YAG to have a good self-Q-switched property whose full width at half maximum is about 4.2ns. Its highest laser power is about 5.7mW. Its peak power is about 150W. Its good fundamental transverse TEM_{00} mode results from the absorption bleaching established by both the pump and oscillating lasers, which suppress other transverse mode and allow the oscillation only in the fundamental transverse TEM_{00} mode.