A coherent beam combination system based on double PZT phase modulators
A novel coherent beam combination system based on double piezoelectric ceramics transducer (PZT) phase modulators is presented and demonstrated for the first time. In this system, two different PZT phase modulators are used for high frequency phase modulation and low frequency phase control, respectively, while in previous demonstrated system, LiNbO3 phase modulators are often employed. The inherent low insert loss and high laser-induced damage threshold of the PZT phase modulator makes the new proposed system more compact and stable. By the way, the experiment of coherent beam combination of two 5-W fiber laser beams based on double PZT phase modulators is done. In the experiment, the PZT phase modulator with 500-kHz frequency response point made in home is used for high frequency phase modulating and another one with 0∼30-kHz linear frequency response range for phase controlling. When the phase control system is in the closed loop, the fringe contrast of far-field intensity pattern is improved to be more than 90 % from 5 % in open loop.
- 9.The characteristics of LiNbO3 phase modulator made by JDSU, available on http://www.jdsu.com/en-us/Optical-Communications/Products/a-z-product-list/Pages/modulator-specialty-and-custom.aspx
- 10.The datasheet of NIR-MPX series-1000 nm band phase modulators, available on http://www.photline.com/product/Modulators/
- 12.PZ1 high-speed fiber stretcher, available on http://www.optiphase.com/products.html