Modified 1×2 directional coupler waveguide modulator

Polymer-Based Hybrid-Integrated Photonic Devices for Silicon On-Chip Modulation and Board-Level Optical Interconnects

“…Bias-free Y-fed directional coupler (YFDC) modulators have been shown to provide better linear transfer functions compared to the sine-squared transfer curve of conventional MZI modulators [33,34]. The device linearity can be further enhanced when the YFDC modulators are incorporated with the Δβ-reversal technique to suppress IMD3s [33,[35][36][37][38].…”

“…The device linearity can be further enhanced when the YFDC modulators are incorporated with the Δβ-reversal technique to suppress IMD3s [33,[35][36][37][38]. We previously demonstrated a polymer based 2-domain YFDC modulator with Δβ-reversal at low modulation frequencies as a proof of concept [as shown in Fig.…”

“…In our device structure, considering the alignment of the RF modulation field with the direction of the 33  in the poled EO polymer film, which is in vertical direction, a microstrip line is a natural choice for the best RF-optical signal overlap integral. Fig.…”

“…9 (a) shows that the modulator has a V π of 1.8V. The effective EO coefficient can be calculated as follows, 33, 3…”

“…EO polymer based optical modulators offer several advantages over the mature lithium niobate (LiNbO 3 ) modulators due to the exclusive properties of polymer materials [2,[6][7][8][9]. EO polymers can be engineered to have very large EO coefficients, γ 33 , which is advantageous for sub-volt half-wave switching voltage (V π ) [10][11][12]. For example, CDL1/PMMA, an EO polymer with γ 33 =60pm/V, was used to achieve V π =0.8V [10].…”