MEMS device with integrated mirror position sensor
Methods and systems for using a dual sided MEMS mirror for determining a direction of a LiDAR beam are disclosed. In one example a MEMS package includes a dual sided MEMS mirror that is manipulable about two orthogonal axes. A first surface of the MEMS mirror is used to steer a LiDAR beam that is used to perform LiDAR imaging of an area of interest. As the mirror is moved, a second surface of the mirror reflects a sensing beam onto a position sensitive device. Data from the position sensitive device is used to determine a position of the mirror which can be used to determine a direction of the steered LiDAR beam.
1. An electro-mechanical component comprising:
a MEMS device including a manipulable mirror having a first reflective surface positioned opposite and spaced apart from a second reflective surface;
a transparent window positioned adjacent a top surface of the MEMS device;
a package base positioned adjacent a bottom surface of the MEMS device;
a laser source coupled to the package base;
a position sensitive device positioned adjacent the second reflective surface and coupled to the package base; and
a package base that is attached to the MEMS device with a first hermetic seal,
wherein the transparent window is attached to the MEMS device with a second hermetic seal.
2. The component of claim 1 wherein the laser source is positioned to direct a sensing beam onto the second reflective surface.
3. The component of claim 1 wherein the position sensitive device is positioned to receive a reflected sensing beam reflected from the second reflective surface.
4. The component of claim 1 further comprising a substrate that receives the MEMS device and is sealed to both the transparent window and to the package base.
5. The component of claim 1 wherein the package base comprises a semiconductor material and the position sensitive device is integrated within the package base.
6. A method of using an electromechanical component comprising:
receiving a first light beam through a window of the component;
steering a reflection of the first light beam through the window by reflecting the first light beam off a first surface of a mirror positioned within the component;
generating a second light beam using a laser source positioned external to the component;
directing the second light beam through a second window towards a second surface of the mirror;
steering a reflection of the second light beam using the second surface of the mirror, wherein the second surface of the mirror is opposite and adjacent the first surface of the mirror; and
receiving the reflection of the second light beam with a position sensitive device positioned external to the component,
wherein the window, the mirror, and second window are integrated into a hermetically sealed silicon-based package.
7. The method of claim 6 further comprising regulating a power of the second light beam using a power control circuit that receives an input signal from the position sensitive device.
8. The method of claim 6 wherein the first light beam is generated by a LiDAR beam generator.