External cavity laser with continuous tuning of grid generator

A laser having a grid generator that is configured such that the grid transmission peaks can be changed or varied during laser operation. The grid generator is tunable between at least two different, selectable grid spacings. The laser may be of various configurations, and may be a tunable external cavity laser having a channel selector in the external cavity. The laser may further comprise a tuner or tuning assembly operatively coupled to the grid generator and configured to adjust the grid generator to the selectable communication grids.