Apparatus is disclosed for optically steering an optical beam, the apparatus comprising a pair of optical prism components arranged together with a diffraction grating so as to allow efficient coupling of an array of spectrally and spatially offset laser diodes to a common optical fiber. A method of optically steering at least one of a series of optical beams is disclosed, the method comprising providing a pair of optical prism components comprising a thermo-optic material; actuating at least one of the components so as to steer at least one of the series of optical beams received from an array of spatially and spectrally offset lasers.