COL Cover Story: Optical property measurements of 235 mm large-scale Ti:Sapphire crystal
At: 2018/7/20 13:53:58 by admin

The emergence of ultra-intense and ultrashort lasersystem makes it possible to attain the extreme conditions in the laboratorylike ultrastrong electric field, ultrahigh magnetic field, ultrahigh energydensity, and gigantic light pressure, which are otherwise found only in theinterior of a star or the edge of a black hole. It has largely promoted thedevelopment of a number of basic and frontier interdisciplinary subjectsincluding laser science, attosecond optics, and plasma physics. Ultra-intenseultrashort laser applications have made some progress in studying antimatter, protonimaging, and driving the wake field electron acceleration.

At present, the main technology of constructingultra-intense and ultrashort laser facility in the world is chirped pulseamplification technologyCPA. Ti sapphire crystal is usually chosen as terminalamplifier in the laser facility based on CPA technology. In order to furtherimprove the peak power of laser pulse, a larger Ti:Sapphire crystal with highquality is required.

The research team led by Yin Hangfrom ShanghaiInstitute of Optics and Fine Mechanics, Chinese Academy of Sciences, used heatexchange method (HEM) to grow a Ti:Sapphire crystal with a diameter of 235 mmand a thickness of 72 mm.the largest Ti:Sapphirecrystal ever reported for a petawatt femtosecond-class laser system. Optical and laser properties were measured. Themeasurement results show that the crystal has good absorbability for 527 nmgreen light. Figure of merit (FOM) value is high. Internal quality of thecrystal is better. And small signal gain value with high uniformity isobtained. The results have been published in Chinese Optics Letters, Vol 16,Issue 7, 2018H. Cao et al.,Opticalproperty measurements of 235 mm large-scale Ti:Sapphire crystal.

Huang Pei, a member of the research team, thinks thatthe study demonstrates that the large Ti:Sapphire crystal has excellent opticalproperties and laser performances, which can further support higher peak powerof the laser pulse output.

Based on the above research results, the next stepwill be to increase the input energy and test the gain under large input energy.

 

Graphic Description: A Ti:Sapphirecrystal with a diameter of 235 mm and a thickness of 72 mm was grown by heatexchange method


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