On-Wafer Optical Loss Measurements Using Ring Resonators With Integrated Sources and Detectors

Abstract

We demonstrate for the first time a fully integrated test structure dedicated to on-wafer propagation loss measurement. An integrated light source is used in combination with a resonant cavity and a full absorbing detector. It is fabricated in a multi project wafer run in an InP based foundry process. The probing of the integrated light source and detector with electrical signals avoids the reproducibility issues and time-overhead associated with high-precision optical alignment. The measurement accuracy, estimated to be $ AE0:2 dB, the compact footprint ð$1:5 mm 2 Þ, and the simple and fast measurement procedure make this approach an ideal candidate for the future characterization of propagation losses in both research and manufacturing environments.

Low-loss passive waveguides in a generic InP foundry process via local diffusion of zinc

“…To verify the low loss of the not p-doped shallow waveguides we used a second test structure based on a all-pass ring resonator, which has been extensively described for various material platforms [21][22][23]. Recently this ring resonator has been applied for the measurement of optical loss [9]. In this work, we increase the measurement sensitivity by increasing the ring circumference from a few millimeter to several centimeter.…”

“…To keep the number of regrowth steps as small as possible, an identical doped waveguide structure is used for phase modulators and passive waveguides, which compromises their performance. A typical loss value for PICs fabricated with this method is 2 dB/cm to 3 dB/cm [9].…”

Structural Optimization of Silica-Based 2 X 2 Multimode Interference Coupler Using a Real-Coded Micro-Genetic Algorithm

“…A multimode interference (MMI) coupler is an important and widely used component in photonic integrated circuits (PICs), such as 3-dB couplers [1][2][3], optical hybrids [4][5][6], multi/demultiplexers for mode-division multiplexing (MDM) transmission [7,8], Mach-Zehnder interferometers for wavelength meters [9], and differential phase shift keying (DPSK) demodulators [10]. An MMI coupler with M input and N output access waveguides is referred to as an M × N MMI coupler.…”

“…An MMI coupler with M input and N output access waveguides is referred to as an M × N MMI coupler. The most widely used application of a MMI coupler is possibly the 2 × 2 MMI coupler as a 3-dB coupler [1][2][3][4][5].…”

“…To fabricate PICs, the most promising and widely used materials are Si nano wire [1,7,8,10], InP [2,3,6,9], and silica [4,5,11]. All these materials have drawbacks and advantages.…”