Text this: Light guiding properties of negative-curvature hollow-core fiber

 _____       ___     __   __    _____     ______  
|  __ \\    / _ \\   \ \\/ //  |  ___||  /_   _// 
| |  \ ||  | / \ ||   \   //   | ||__    `-| |,-  
| |__/ ||  | \_/ ||   / . \\   | ||__      | ||   
|_____//    \___//   /_//\_\\  |_____||    |_||   
 -----`     `---`    `-`  --`  `-----`     `-`'