a light beam scanner of the moving interference fringe pattern type which includes a body of semiconductor material having a source of coherent radiation and wave guides for guiding the coherent radiation along a plurality of spatially displaced paths which are optically uncoupled , and means associated with the spatially displaced paths for producing relative phase changes between radiation in the different paths whereby interference fringes in the far field are spatially scanned . in addition , wavelength modulation of the laser over a range of about 80 a can be achieved . the source of the coherent radiation can be a single laser or a plurality of optically coupled lasers , and the optical uncoupling can be achieved by spatial displacement of the paths or by insertion of a high loss medium between the paths .