Abstract: A tunable spectral source includes an enclosure having first and second apertures; an optical dispersive element positioned in the enclosure; and multiple pixel source elements that are individually controllable for selectively directing one or more broadband light signals through the first aperture to irradiate the optical dispersive element. Each of the broadband light signals irradiates the optical dispersive element at a unique angle of incidence. The optical dispersive element disperses the broadband light signals into spectral component signals at dispersion angles that are dependent upon the angle of incidence of each broadband light signal that irradiates the optical dispersive element. The portions of the spectral component signals that are emitted through the second aperture are determined by selecting one or more particular pixel source elements to irradiate the optical dispersive element.