OCI1500 is an ultra-high resolution optical link diagnostic and distributed optical fiber sensing instrument. The principle of this product is optical frequency domain reflection (OFDR). Its spatial resolution is 10um in 50m range. OCI1500 can easily find and determine macro bends, weak splicing points, connection points, breakpoints and spectrum, return loss and insert loss in the fiber link. The fiber length can be accurately measured by OCI1500 and the accuracy is 0.1mm. Besides, OCI1500 can also realize distributed temperature and strain measurement.