Peripheral-Coupled-Waveguide MQW Electroabsorption Modulator for Near Transparency and High Spurious Free Dynamic Range RF Fiber-Optic Link

Abstract

Abstract-Peripheral coupled waveguide (PCW) design has been deployed in InGaAsP multiple quantum-well (MQW) electroabsorption modulator (EAM) at 1.55-m wavelength. PCW enhances the optical saturation power and reduces the optical insertion loss and the equivalent V simultaneously. A radio-frequency link using a 1.3-mm-long lumped-element PCW EAM has achieved experimentally a link gain of 3 dB, at 500 MHz and at input optical power of 80 mW. The corresponding two-tone multioctave spurious-free dynamic range (SFDR) at the same bias is measured at 118 dB Hz 2 3 . The single-octave SFDR at the third-order null bias is 132 dB Hz 4 5 . Index Terms-Electroabsorption modulator (EAM), peripheral coupled waveguide (PCW), radio-frequency (RF) link gain, spurious-free dynamic range (SFDR).

Characterization of an electroabsorption modulator design with high-dynamic range for broadband analog applications

“…Electroabsorption modulators have been shown to exceed the dynamic range of other optical approaches such as waveguide integrated Mach Zehnder modulators [2]. This has been achieved by Paul Yu at UCSD using several designs on probed waveguides in a laboratory setting.…”

“…It was well known that transmission and matching of electrical signals, as well as optical fiber to waveguide interfacing, posed significant challenges to realizing the performance of a waveguide chip in a laboratory. The latter's impressive dynamic range results, with useful gain over a large span of frequencies beyond 20 GHz, were influential in motivating this work [2,3]. To take this to another stage in the process necessary to qualify such technology for higher levels of system readiness, an essential step is a sealed packaged product shown in Figure 1 and is suitable for insertion in various brass-board test configurations.…”

Wideband Electroabsorption Modulator for Microwave Photonics

“…Furthermore, the optical waveguide will have a large mode size that matches to the single-mode fiber mode. The details of the design are reported in [3].…”

“…To demonstrate this concept, a PCW-EAM with a lumped-electrode is fabricated [3], in which the p-I(MQW)-n structure is grown on semi-insulating InP. The active region …”

High Power MQW Electroabsorption Modulator with a Waveguide Taper

“…Recently, an EAM based on a peripheral coupled waveguide (PCW) was proposed to reduce the electroabsorption saturation by substantially reducing the optical confinement factor Γ at the electroabsorption region [3]. In the PCW, the electroabsorption region is placed only peripheral to a large optical waveguide mode, in its evanescent field.…”