Silicon-based Modulation Depth Adjustable Dual Cascade Modulator and Its High Linear Method for Microwave Photonic Links

Abstract

The invention discloses a silicon-based modulation depth-adjustable double-cascade modulator and a microwave photon link high-linearity method thereof. Silicon-based MZM1 and MZM2 based on a carrier depletion mode and a TROPS are included; and the TROPS is cascaded between the MZM1 and the MZM2. An optical signal output by the laser passes through the polarization controller and is coupled to theDSMZMs through the optical fiber coupler, a modulated small signal is loaded on the DSMZMs through the 50 / 50 EPS, and the DSMZMs are directly detected at a link receiving end through the photodiode. The distribution ratio gamma of the TROPS is adjusted to control the modulation depth of the MZM2; meanwhile, the MZM1 and MZM2 direct-current reverse bias voltages and bias working points are regulated and controlled; IMD3 signals in the two modulators are mutually inhibited, so that a high-linearity microwave photon link based on the silicon-based modulator is realized, and the relationship between the FH and IMD3 signal changes of the DSMZMs and reverse bias direct current voltage and gamma is theoretically deduced and analyzed in detail.

Description

technical field [0001] The invention relates to a silicon-based modulation depth-adjustable dual-cascade modulator and a microwave photon link high linearity method based on the silicon-based modulation depth-adjustable dual-cascade modulator, in particular to a method including adjustable distribution ratio optical power A high linearity method for microwave photonic links of Dual-series Mach-Zehnder Modulators (DSMZMs) of tunable-ratio Optical Power Splitter (TROPS). Background technique [0002] In recent years, microwave photonic technology, which combines microwave technology and light wave technology, has been widely used in cable television, fiber optic wireless systems, etc. It mainly studies how to use optoelectronic devices and methods to realize the generation, transmission distribution, and processing of microwave / millimeter wave signals. With the development of technology, microwave photonic technology requires devices and systems to have small size, light weig...

AI Technical Summary

Problems solved by technology

The electro-optical modulator responsible for photoelectric conversion is a key component of the microwave link of the system. The nonlinearity of its transfer function will bring distortion to the link and affect the linearity of the microwave link.

[0005] Among various silicon-based electro-optic modulators, the silicon-based MZM based on the Mach-Zehnder interference structure is most widely used in microwave photonic links due to its advantages of high speed, high extinction ratio, low insertion loss and simple fabrication. The highly linear microwave photonic link of silicon-based MZM proposes a variety of linearization schemes to suppress IMD3, for example, by changing the doping concentration of the modulation arm in the silicon-based modulator to change the overlapping region of the optical field and the electric field to achieve a highly linear link There are also optical nonlinear DC-Kerr effects to compensate the nonlinearity of carriers and sinusoidal modulation curves in silicon-based modulators, but these two methods change the process flow of chip foundries and increase the complexity of chip processing and cost

[0006] In addition, imitating the realization principle of the lithium niobate high linearity modulator with parallel MZM structure, it is also possible to achieve silicon-based high linearity by adjusting the optical power distribution ratio of silicon-based parallel MZM, the bias operating point, and the optical power distribution ratio of modulated small signals. Modulator, but this method has higher operational complexity and more monitoring and control variables

At present, there is no similar report on the cascaded silicon-based MZM, especially the cascaded MZM including the adjustable distribution ratio optical power splitter has not been reported in other material modulators.

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