Self-mixing interference device with tunable microelectromechanical system
AssigneeApple Inc.
InventorsTong Chen, Ahmet Fatih Cihan, Edward Vail, Weiping Li, Xiaolong Fang, Xibin Zhou, Pengfei Qiao
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Abstract
Self-mixing interferometry (SMI) sensors may include vertical cavity surface emitting lasers (VCSEL), photodetectors, and microelectromechanical systems (MEMS). The VCSEL, photodetectors, and MEMS may be vertically stacked. The MEMS may be moveable with respect to a VCSEL and may change a cavity length associated with the VCSEL. By changing the cavity length associated with the VCSEL, certain properties of emitted light may be changed, such as a wavelength value of the emitted light.
Claims20
A self-mixing interferometry (SMI) sensor comprising:
- a photodetector comprising a first set of semiconductor layers formed on a substrate;
- a vertical cavity surface emitting laser (VCSEL) stacked with the photodetector and comprising a second set of semiconductor layers formed on the first set of semiconductor layers;
- and
- a microelectromechanical system (MEMS) stacked with the VCSEL on a side opposite from the photodetector and comprising an at least partially reflective layer, wherein:
- the VCSEL is configured to emit light;
- and
- the MEMS is configured to change a length of a resonant cavity associated with the VCSEL, thereby changing a property of the emitted light.
A tunable sensor for performing self-mixing interferometry, the tunable sensor comprising:
- a vertical cavity surface emitting laser (VCSEL) comprising a laser cavity;
- a microelectromechanical system (MEMS) comprising an at least partially reflective layer defining an end of the laser cavity;
- and
- a photodetector positioned to receive light emitted by the VCSEL after the light passes through the at least partially reflective layer, wherein a position of the at least partially reflective layer, which is moved when a voltage is applied to the MEMS, defines a length of the laser cavity.
A self-mixing sensor comprising:
- a substrate;
- a first set of semiconductor layers positioned above the substrate, the first set of semiconductor layers operating as a first light receiving or light emitting element;
- a second set of semiconductor layers stacked with the first set of semiconductor layers, the second set of semiconductor layers operating as a second light receiving or light emitting element;
- and
- a microelectromechanical system (MEMS) stacked with the second set of semiconductor layers, the MEMS comprising a moveable reflective layer.
Dependencies are inferred from the claim text.