Laser written waveguides to the sample edge

Area of Science:

• Photonics and Optical Engineering
• Materials Science and Engineering

Background:

• Femtosecond laser writing is a key technique for fabricating optical waveguides in glass.
• Edge aberrations and the need for substrate polishing can limit the performance and applicability of laser-written waveguides.

Purpose of the Study:

• To develop a method for fabricating femtosecond laser waveguides in glass that bypasses the requirement for post-processing polishing.
• To improve the coupling efficiency between optical fibers and photonic circuits fabricated without polishing.

Main Methods:

• Amplitude masking of the fabrication laser beam near the sample edge.
• Controlled increase of pulse energy during waveguide writing.
• Fabrication of waveguides at various depths in fused silica and borosilicate glass.

Main Results:

• Waveguides were successfully written without being affected by edge aberrations.
• The fabricated waveguides exhibited mode profiles well-matched to single-mode fiber.
• Significantly improved transmission from fiber to photonic circuit was achieved.

Conclusions:

• The developed amplitude masking technique enables the fabrication of high-performance laser-written waveguides without post-processing polishing.
• This method offers new possibilities for photonic packaging and integration, particularly in scenarios where polishing is impractical.