A new method for fiber chromatic dispersion measurement with microwave interference effect

• Fiber chromatic dispersion (CD) measurement with microwave interference effect was proposed.
• Phase noise produced by the environmental variations to the fiber link could be counteracted.
• The RF frequency can be chosen flexibly according to the CD amount of the fiber.
• The CD sign can be determined easily by inserting a reference fiber.

The chromatic dispersion (CD) is a key parameter for optical fibers. Based on the microwave interference effect, a new method for CD measurement of optical fibers is proposed. The radio frequency (RF) signals carried by two light-waves with different wavelengths transmit through the dispersive optical fiber under test. After photo-detector they interfere with each other due to the different phase shifts induced by the CD of fiber. The CD can be obtained by monitoring the changing interference RF power with scanning the wavelength of tunable laser source. The CD values of single mode fiber and dispersion compensating fiber are measured within the wavelength range from 1525 to 1605 nm. The common phase shift method is used to measure the CDs of the two types of fiber, which demonstrates the feasibility and veracity of the proposed method.