Optical sensor module including a diode laser and a substrate transparent to radiation emitted by the diode laser and a method for manufacturing an optical sensor module

• US 8,378,287 B2
• Filed: 06/23/2008
• Issued: 02/19/2013
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: TRUMPF Photonic Components GmbH (TRUMPF SE + Co. KG)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Pruijmboom, Armand, Booij, Silvia Maria, Werner, Klaus Peter, Schemmann, Marcel Franz Christian
• Primary Examiner(s): LUU, THANH X
• Application Number:
  US12/665,124
• Publication Number:
  US 20100187449A1
• Time in Patent Office: 1,702 Days
• Field of Search: 250/551, 250/221, 250/239, 345166-168, 372/29.011, 372/38.01
• US Class Current: 250/221
• CPC Class Codes: G06F 3/0317 in co-operation with a patterned surface, e.g. absolute position or relative movement detection for an optical mouse or pen positioned with respect to a coded surface
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01S 5/0028 Laser diodes used as detectors
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/0234 Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings
• CPC Class Codes: H01S 5/0683 by monitoring the optical output parameters
• CPC Class Codes: H01S 5/18388 Lenses

Abstract

The invention relates to an optical sensor module (1) for a measuring device. Said module comprises at least one optical sensor (2) including a diode laser (3) having a laser cavity for generating a measuring beam, the diode laser being attached to a substrate (12), converging means (5) (such as a lens). During measuring, such converging means (5) converges the measuring beam in an action plane and converges in the laser cavity the measuring beam radiation that has been back-scattered by an object to generate a self-mixing effect and means for measuring the self-mixing effect. Later means comprise a photo diode (4) and an associated signal processing circuitry. According to an essential aspect of the invention, that the diode laser (3) is configured to emit laser radiation of a wavelength for which the substrate (12) being attached to the diode laser (3) is transparent. This configuration leads to an essentially simple (and therefore cheap) sensor module.

Claims

1. Optical sensor module for a measuring device, which module comprises at least one optical sensor including a diode laser having a laser cavity for generating a measuring beam, the diode laser being attached to a substrate, converging means for converging the measuring beam in an action plane and for converging in the laser cavity measuring beam radiation that has been back-scattered by an object to generate a self-mixing effect and means for measuring the self-mixing effect, which means comprise a photo diode and an associated signal processing circuitry, wherein the diode laser is configured to emit laser radiation through said substrate, said laser radiation having a wavelength for which the substrate being attached to the diode laser is transparent, said converging means being arranged on a side of the substrate and the diode laser being attached to the other side of the substrate, said photo diode functioning as a carrier for said diode laser, said diode laser and said photo diode being mutually mechanically and electrically connected.

2. Optical sensor module according to claim 1, comprising successively in the direction of the emitted measuring beam, a carrier, the photo diode and a Vertical Cavity Surface Emitting Laser (VCSEL)-type diode laser, the substrate being attached to the diode laser being turned away from the photo diode.

3. Optical sensor module according to claim 1, wherein at least two diode lasers are arranged with respect to a single converging means such that the measuring beams from the diode lasers pass this converging means at different areas.

4. Optical sensor module according to claim 1, wherein the sensor module further comprises a base of a module encapsulation, which on the opposite side of the sensor module is closed by a transparent plate.

5. Optical sensor module according to claim 4, wherein the converging means are diffraction converging means, wherein the encapsulation is filled up with a transparent material and wherein an upper side of the transparent material forms the transparent plate.

6. A method of manufacturing an optical sensor module, wherein the method comprises the following steps:

manufacturing on a wafer scale an array of diode lasers,

slicing the array of diode lasers to obtain diode laser sets having a required number of diode lasers;

manufacturing on a wafer scale an array of photo diodes corresponding to the array of diode lasers,

arranging the sets of diode lasers on corresponding sets of photo diodes and fixing the sets together, wherein a first side of each of said diode lasers arranged on the corresponding sets of photo diodes includes a respective substrate and wherein said fixing comprises fixing second sides of the sets of diode lasers that oppose said first sides to said sets of photo diodes;

slicing the array of photodiodes to obtain individual combined diode laser/photo diode sets;

combining the sets with one of an array of integrated circuits for processing measured signals and for controlling the diode lasers, wherein said array of integrated circuits has been manufactured on a wafer scale, to obtain individual module devices having the required number of diode lasers and photo diodes, and

mounting one of said module devices on a carrier and encapsulating the one of said module devices.

7. Method according to claim 6, comprising an intermediate step of providing each set of photo diodes belonging to one module device with one radiation converging element before slicing the array of photo diodes.

8. Method according to claim 6, wherein said fixing comprises fixing said sets of diode lasers to said sets of photo diodes such that each of said diode lasers of said sets of diode lasers is disposed directly above a corresponding photo diode of the sets of photo diodes.

9. Method according to claim 6, wherein said fixing comprises fixing said sets of diode lasers to said sets of photo diodes such that each of said diode lasers of said sets of diode lasers is mutually mechanically and electrically connected to a corresponding photo diode of the sets of photo diodes.

10. Optical sensor module for a measuring device, which module comprises at least one optical sensor including at least two diode lasers having laser cavities for generating measuring beams, the diode lasers being attached to a substrate, converging means for converging the measuring beams in an action plane and for converging in the laser cavities measuring beam radiation that has been back-scattered by an object to generate a self-mixing effect and means for measuring the self-mixing effect, which means comprise a photo diode and an associated signal processing circuitry, wherein the diode lasers are configured to emit laser radiation through said substrate, said laser radiation having a wavelength for which the substrate being attached to the diode lasers is transparent, said converging means being arranged on a side of the substrate and the diode lasers being attached to an other side of the substrate, said photo diode functioning as a carrier for said diode lasers, said diode lasers and said photo diode being mutually mechanically and electrically connected, wherein the converging means is a single converging means and wherein the at least two diode lasers are arranged with respect to the single converging means such that the measuring beams from the diode lasers pass the single converging means.