Lasers based on vibronic crystal Ti:Sapphire (also known as Ti:Al2O3 lasers, titanium-sapphire lasers, Ti:sapp, Ti:S, Ti:Sa, Ti-Sapp or simply Ti:sapphs) are used widely in research as they are tunable and capable of ultra-short pulses from a few picoseconds (ps) to tens of attoseconds (as), typically tens of femtoseconds (fs) in duration. Ti:Sapphire preferentially emits in the region of 800nm, but the crystal is capable of a tuning range spanning 650nm to 1100nm. Often referred to as an oscillator, this laser is created by pumping the titanium ion doped sapphire crystal with a laser at a shorter wavelength.
By fixing the relationship between the longitudinal modes of the laser, the output is said to be “mode locked” where the modes constructively interfere with each other to generate these short pulses. Typical applications include CEP (Carrier Envelope Phase) stabilisation, two photon microscopy, terahertz spectroscopy, Optical Coherence Tomography (OCT), micromachining, frequency combs, and other “ultrafast” techniques or as part of a larger amplifier system.
The green pump laser is a crucial component of the oscillator as it is the source of the initial photons that cascade through the system. The pump laser quality therefore has a direct correlation with the quality of the light exciting the Ti-Sapp crystal and therefore the emitted light. A pump laser with excellent beam quality, good power stability and low amplitude noise, will result in more stable, low noise Ti:Sapp output pulses. The pump laser has traditionally been an argon ion laser, but although they can achieve high power and beam quality, they are large, inefficient with relatively short lifetimes and high running costs. 532nm DPSS pump lasers offer an alternative to the argon ion lasers and have become the pump laser of choice as they achieve high powers with good beam quality, but have the added advantage of higher wall plug efficiency, longer lifetimes, a smaller footprint and require minimal cooling.
Laser Quantum offer a number of lasers that are suitable for this application depending on the power requirement, noise level needed and the size of the system to be used.
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|Abstract - High energy 1Hz Ti:Sapp amplifier for Petawatt laser||215KB|
|Scientific paper - Ti:Sapp Pumping||730KB|
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|Presentation - Noise considerations||1505KB|