Noninterferometric and nontomographic iterative method for field retrieval

A new method of field recovery is proposed based on the fact that an arbitrary light beam can be expressed as a finite sum over orthogonal field distributions with unknown coefficients. If these field distributions are eigenmodes of a specific waveguide, the coefficients of the field decomposition in orthogonal eigenmodes can be determined iteratively when the unknown field is passed through a series of waveguides that support an increasing number of modes. This series of waveguides can be replaced by a single reconfigurable electro-optic waveguide, which one can use to recover the unknown field by performing only intensity measurements.