Directly written waveguide for coupling of laser to photonic integrated circuit

Abstract

Systems, devices, and methods of manufacturing optical engines and laser projectors that are well-suited for use in wearable heads-up displays (WHUDs) are described. Generally, the optical engines of the present disclosure integrate a plurality of laser diodes (e.g., 3 laser diodes, 4 laser diodes) within a single, hermetically or partially hermetically sealed, encapsulated package. Photonic integrated circuits having grating or edge couplers thereon may be used to wavelength multiplex beams of light emitted by the plurality of laser diodes into a coaxially superimposed aggregate beam. A waveguide medium having one or more directly written waveguides may couple light from laser diodes to a photonic integrated circuit, and may optionally hermetically or partially hermetically seal the laser diodes, eliminating the need for a separate seal. Such optical engines may have advantages over existing designs including, for example, smaller volumes, better manufacturability, faster modulation speed, etc. WHUDs that employ such optical engines and laser projectors are also described.

Description

BACKGROUNDTechnical Field[0001]The present disclosure is generally directed to systems, devices, and methods relating to optical engines, for example, optical engines for laser projectors used in wearable heads-up displays or other applications.Description of the Related Art[0002]A projector is an optical device that projects or shines a pattern of light onto another object (e.g., onto a surface of another object, such as onto a projection screen) in order to display an image or video on that other object. A projector necessarily includes a light source, and a laser projector is a projector for which the light source comprises at least one laser. The at least one laser is temporally modulated to provide a pattern of laser light and usually at least one controllable mirror is used to spatially distribute the modulated pattern of laser light over a two-dimensional area of another object. The spatial distribution of the modulated pattern of laser light produces an image at or on the ot...

AI Technical Summary

Benefits of technology

The patent describes an optical engine that includes a base substrate, laser diodes, a laser diode driver circuit, a photonic integrated circuit, and a waveguide medium. The laser diodes are bonded to the base substrate and the driver circuit controls which ones are activated. The photonic integrated circuit includes input and output facets and receives the laser beams from the laser diodes. The waveguide medium includes at least one directly written waveguide that couples the laser beams to the input facet. The optical engine has various technical effects, including improved laser beam collimation, wavelength dependent focus correction, and the ability to couple multiple laser beams to a single photonic integrated circuit.

Problems solved by technology

However, in applications for which the form factor of the laser projector is an important design element, it can be very challenging to find a configuration for the laser diodes, the focusing lenses, and the at least one controllable mirror that sufficiently aligns the laser beams (at least in terms of spot size, spot position, and rate of convergence) while satisfying the form factor constraints.

A wearable heads-up display is a head-mounted display that enables the user to see displayed content but also does not prevent the user from being able to see their external environment.

Independent of their performance limitations, many of the aforementioned examples of wearable heads-up displays have struggled to find traction in consumer markets because, at least in part, they lack fashion appeal or comfort.

Most wearable heads-up displays presented to date employ relatively large components and, as a result, are considerably bulkier, less comfortable and less stylish than conventional eyeglass frames.

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