Various optoelectronic modules are described that include an emitter operable to produce light (e.g., electromagnetic radiation in the visible or non-visible ranges), an emitter optical assembly aligned with the emitter so as to illuminate an object outside the module with light produced by the emitter, a detector operable to detect light at one or more wavelengths produced by the emitter, and a detector optical assembly aligned with the detector so as to direct light reflected by the object toward the detector. In some implementations, the modules include features for expanding or shifting the linear photocurrent response of the detector.