Beam shaping of a broad-area laser diode using 3D integrated optics

Area of Science:

• Optics
• Photonics
• Materials Science

Background:

• High power broad-area semiconductor lasers produce astigmatic beams unsuitable for many applications.
• Coupling these lasers into circular multimode optical fibers degrades beam quality due to mode mixing.

Purpose of the Study:

• To develop an integrated optics solution for shaping the output of broad-area laser diodes.
• To improve beam quality and brightness compared to traditional fiber coupling methods.

Main Methods:

• Utilized ultrafast laser inscription to fabricate a 3D integrated photonic chip.
• Designed a photonic chip with back-to-back photonic lanterns to capture and reshape laser output.
• Tested a commercial 976 nm broad-area laser diode with a 95 μm emitter width.

Main Results:

• The photonic chip successfully captured and shaped the astigmatic laser diode output.
• Achieved a 13x higher beam quality compared to direct fiber coupling.
• Demonstrated a 7x greater brightness with the integrated photonic chip approach.

Conclusions:

• The 3D integrated optics approach using photonic lanterns is an effective method for beam shaping.
• This chip-based solution offers significant improvements in beam quality and brightness for laser diode applications.
• Offers a promising alternative to conventional fiber coupling for achieving high-quality laser beams.