Abstract
Ti:sapphire presents unequaled tuning properties. However, because of a short lifetime, the energy cannot be stored in Ti3+ upper level, which makes this gain medium difficult to pump. Hence, the size, price, and complexity of femtosecond laser chains are partially driven by their pump source. We present a novel concept to pump Ti:sapphire, based on light-emitting diodes (LEDs), that gathers ruggedness, compactness, simplicity, and low price. By combining LEDs and a Ce:LuAG luminescent concentrator, we report the first LED-pumped Ti:sapphire laser, to the best of our knowledge. With 2240 blue LEDs (at 450 nm) in pulsed regime (10 Hz, 15 μs), the pump module has a maximum emission at 530 nm and delivers up to 20.9 mJ with an irradiance of 9.9 kW/cm2. This low-cost and compact pump system, among the brightest incoherent sources ever developed, enables laser emission in Ti:sapphire (32 μJ at 790 nm). The tunability of the laser is demonstrated between 755 and 845 nm. The double-pass small signal gain in the cavity is numerically simulated and measured to reach 1.066.
Highlights
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not
The documents may come from teaching and research institutions in France or abroad, or from public or private research centers
We present a novel concept to pump Titanium-doped sapphire (Ti):Sapphire based on light-emitting diodes (LEDs) which gathers ruggedness, compactness, simplicity and low price
Summary
With 2240 blue LEDs (at 450 nm) in pulsed regime (10 Hz, 15 μs), the pump module has a maximum emission at 530 nm and delivers up to 20.9 mJ with an irradiance of 9.9 kW/cm2 This low-cost and compact pump system, among the brightest incoherent sources ever developed, enables a laser emission in Ti:sapphire (32 μJ at 790 nm). LEDs are incoherent sources with limited irradiance: typically, in the order of 100 W/cm2 This is enough to demonstrate the LED-pumping of Nd:doped lasers [13,14,15,16,17] but not for Ti:sapphire. With the beam collection of 1120 LEDs, the LC is able to provide green flashes with an energy of 13.9 mJ over 15 μs (see Table 1)
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call