Planar waveguides with less than 01 dB/m propagation loss fabricated with wafer bonding

Abstract

We demonstrate a wafer-bonded silica-on-silicon planar waveguide platform with record low total propagation loss of (0.045 ± 0.04) dB/m near the free space wavelength of 1580 nm. Using coherent optical frequency domain reflectometry, we characterize the group index, fiber-to-chip coupling loss, critical bend radius, and propagation loss of these waveguides.

Integrated Microwave Photonics for Wideband Signal Processing

“…Thanks to the CMOS-compatible fabrication technology which promises a more cost effective, robust and compact solution, delay elements based on various chip-scale platforms have been intensively investigated. In particular, low propagation loss has been demonstrated in optical waveguides of wedge geometry, high-aspect-ratio Si3N4, and high-quality silicon oxynitride films [32][33][34][35][36]. In [32], an optical delay line fabricated on a silicon chip has been presented, exhibiting an average measured waveguide loss of 0.08 ± 0.01 dB/m in long spirals.…”

Integrated Ultra-Low-Loss 4-Bit Tunable Delay for Broadband Phased Array Antenna Applications

“…Finally, 1 μm of gold was then deposited as probing pads. Further details on the waveguide fabrication can be found in [8].…”

“…Using a 1-meter spiraled waveguide test structure, the backscattered optical power was measured using a Luna OBR 4400 commercial reflectometer and the propagation loss extracted as in [8]. Figure 4 displays the TE loss as a function of wavelength for the designed waveguide.…”

“…Although many fully integrated optical TTD have been demonstrated [4]- [7], the maximum amount of delay is usually limited by high propagation loss limiting the delay time to the picosecond range or a few nanoseconds. We have recently demonstrated record low propagation losses in a Si 3 N 4 /SiO 2 planar waveguide technology, which allows for long delays to be implemented on chip scale devices [8], [9].…”

Design and characterization of arrayed waveguide gratings using ultra-low loss Si3N4 waveguides

“…At this stage, a silicon dioxide upper cladding may be deposited (as shown in Fig. 1) or bonded to the wafer (as discussed in [1]). For applications requiring active devices, a thin device silicon layer may be bonded instead [2].…”