Optoelectronic module operable for distance measurements
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.
1. An optoelectronic module comprising:
an emitter operable to produce light;
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;
the emitter optical assembly and the emitter being operable, in combination, to expand a range of distances between the optoelectronic module and the object for which photocurrent response of the detector is linear, wherein the linear photocurrent response detected by the detector is correlated to a distance between the optoelectronic module and the object, and wherein the range of distances for which the photocurrent response of the detector is linear is expanded relative to a range of distances between the optoelectronic module and the object for which the photocurrent response of the detector is linear in the absence of the emitter optical assembly.
2. The optoelectronic module of claim 1 wherein the emitter optical assembly includes an anamorphic lens element, the optical assembly and the emitter being operable to tilt an emitter field of view toward the detector.
3. The optoelectronic module of claim 1 , the optical assembly and the emitter being operable to cast an illumination of laterally varying intensity onto the object.
4. The optoelectronic module of claim 1 wherein the emitter optical assembly includes an optical element operable to cast an illumination having discrete illumination features.
5. The optoelectronic module of claim 4 wherein the optical element includes a diffractive optical element.
6. The optoelectronic module of claim 4 wherein each one of the discrete illumination features is operable to produce a respective stepped photocurrent response when detected by the detector.
7. The optoelectronic module of claim 4 wherein at least one of the discrete illumination features has an intensity that differs from another one of the discrete illumination features.
8. The optoelectronic module of claim 1 wherein illumination from the module cast on the object includes geometric shapes or a series of shapes.