www.nature.com/...nature14894.html New frequency record breaking laser in the X-ray New frequency record breaking laser in the X-ray www.nature.com/...nature14894.html www.nature.com/...nature14894.html www.nature.com/...nature14894.html New frequency record breaking laser in the X-ray www.nature.com/...nature14894.html New frequency record breaking laser in the X-ray New frequency record breaking laser in the X-ray New frequency record breaking laser in the X-ray www.nature.com/...nature14894.html