Optical signal can not only transmit signal through optical fibre delay coil, but also obtain optical signal with delay. The delay of optical fibre delay line is determined by the length of the optical fibre and the propagation speed of the light in the optical fibre. Optical fibre delay coil of YOFC is wound by precision winding machine, which has high delay precision, compact structure, anti-seismic and anti-radiation design. We can customize different types and lengths of optical fibre delay coil according to customers’ requirements.