Co-phasing technique is used to detect and compensate the fluctuation of optical path difference (OPD) between subtelescopes of long baseline optical interferometers caused by atmospheric turbulence. At present, the sensitivity of cophasing technology is limited, which cannot meet the observation needs for more and darker objects such as Broad Line Region of Active Galactic Nucleus and Quasars. A kind of chromatic phase diversity method (CPD) used to obtain OPD by extracting phase and unwrapping phase difference from the optical transfer function of multi-aperture interferometry was proposed in 2014. Compared to other traditional co-phasing or fringe tracking methods, this method is of some significant advantages such as less power loss, larger capture range of piston error and synchronous sensing for all apertures. In the past, the method was verified by bulk optics or integrated photonics chip only combining beams. Wavelength Separation was still accomplished by many dichroic beamsplitters and fold mirrors which would increase light loss. We present a new compact solution that Fizeau multi-axial beam combination and multiple spectral channels can be merged on single photonic chip. Our works including Verifying of CPD algorithm, model simulation and design of the chip on H-band will be introduced respectively.
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