An encoder configuration for use in a position sensing device usable to measure a relative position between two elements along a measuring axis direction, the encoder configuration comprising: at least one illumination system (260, 360, 560, 760) including: a light generator (230, 330, 530, 730) that generates a primary light emitted from a primary light emitting area, and a phosphor area (205, 305, 505, 705) arranged to receive the primary light and, in response, to output phosphor light from a phosphor light emitting area; a scale element (210, 310, 510, 710) including a scale pattern (215, 315, 515, 715) extending along the measuring axis direction, the scale pattern arranged to be illuminated by phosphor light from the phosphor light emitting area and to output a spatially modulated phosphor light pattern (SMPHL) along a light path; and a detector electronics (220, 320, 520, 720) comprising a detector portion (225, 325, 525, 725) arranged in a fixed relationship relative to the light generator, and arranged to receive the spatially modulated phosphor light pattern along the light path, wherein the encoder configuration is configured such that: the primary light is distributed to the phosphor area (205,305,505,705) with a first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705) and the phosphor area (205,305,505,705) outputs the phosphor light with a second level of phosphor light intensity uniformity; the phosphor area (205,305,505,705) is configured to include a saturation intensity level wherein for primary light intensities above the saturation intensity level, a ratio of phosphor light intensity increase to primary light intensity increase decreases relative to that ratio below the saturation intensity level; and the primary light is distributed to the phosphor area (205,305,505,705) with a primary light intensity that exceeds the saturation intensity level proximate to the phosphor area, (205,305,505,705) for at least a portion of the phosphor area, (205,305,505,705) such that the second level of phosphor light intensity uniformity is more uniform than the first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705). at least one illumination system (260, 360, 560, 760) including: a light generator (230, 330, 530, 730) that generates a primary light emitted from a primary light emitting area, and a phosphor area (205, 305, 505, 705) arranged to receive the primary light and, in response, to output phosphor light from a phosphor light emitting area; a light generator (230, 330, 530, 730) that generates a primary light emitted from a primary light emitting area, and a phosphor area (205, 305, 505, 705) arranged to receive the primary light and, in response, to output phosphor light from a phosphor light emitting area; a scale element (210, 310, 510, 710) including a scale pattern (215, 315, 515, 715) extending along the measuring axis direction, the scale pattern arranged to be illuminated by phosphor light from the phosphor light emitting area and to output a spatially modulated phosphor light pattern (SMPHL) along a light path; and a detector electronics (220, 320, 520, 720) comprising a detector portion (225, 325, 525, 725) arranged in a fixed relationship relative to the light generator, and arranged to receive the spatially modulated phosphor light pattern along the light path, wherein the encoder configuration is configured such that: the primary light is distributed to the phosphor area (205,305,505,705) with a first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705) and the phosphor area (205,305,505,705) outputs the phosphor light with a second level of phosphor light intensity uniformity; the phosphor area (205,305,505,705) is configured to include a saturation intensity level wherein for primary light intensities above the saturation intensity level, a ratio of phosphor light intensity increase to primary light intensity increase decreases relative to that ratio below the saturation intensity level; and the primary light is distributed to the phosphor area (205,305,505,705) with a primary light intensity that exceeds the saturation intensity level proximate to the phosphor area, (205,305,505,705) for at least a portion of the phosphor area, (205,305,505,705) such that the second level of phosphor light intensity uniformity is more uniform than the first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705). the primary light is distributed to the phosphor area (205,305,505,705) with a first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705) and the phosphor area (205,305,505,705) outputs the phosphor light with a second level of phosphor light intensity uniformity; the phosphor area (205,305,505,705) is configured to include a saturation intensity level wherein for primary light intensities above the saturation intensity level, a ratio of phosphor light intensity increase to primary light intensity increase decreases relative to that ratio below the saturation intensity level; and the primary light is distributed to the phosphor area (205,305,505,705) with a primary light intensity that exceeds the saturation intensity level proximate to the phosphor area, (205,305,505,705) for at least a portion of the phosphor area, (205,305,505,705) such that the second level of phosphor light intensity uniformity is more uniform than the first level of primary light intensity uniformity proximate to the phosphor area (205,305,505,705).