A multispectral beam combiner includes a prism body having an output surface, a fiber entry block attached to the prism body, and a plurality of input fibers attached to the fiber entry block. Each of the plurality of input fibers is operable to support a different wavelength. The multispectral beam combiner also includes a collimator attached to the prism body. The collimator is operable to reflect and collimate light propagating from the fiber entry block. The multispectral beam combiner further includes an immersion grating operable to diffract light propagating from the collimator. The output surface of the prism body is operable to pass light propagating from the immersion grating.