Efficient and wavelength-tunable second-harmonic generation towards the green gap

Achieving compact and efficient visible laser sources is crucial for a wide range of applications. However traditional semiconductor laser technology faces difficulties in producing high-brightness green light, leaving a “green gap” in wavelength coverage. Second-harmonic generation (SHG) offers a promising alternative by converting near-infrared sources to visible wavelengths with high efficiency and spectral purity. Here, we demonstrate efficient and tunable SHG within the green spectrum using a high-Q Si3N4 microresonator On chip green power as high as 5.3 mW is generated with a conversion efficiency of 141%/W (absolute 7.9%). A space-charge grating induced by the photogalvanic effect realizes reconfigurable grating numbers and flexible wavelength tuning over a range of 2.6 THz. Additionally, grating formation dynamics and competition is observed. These findings underscore the potential of Si3N4 as a robust, integrative platform for on-chip, tunable green light sources., , # Efficient and wavelength-tunable second-harmonic generation towards the green gap

Dataset DOI: [10.5061/dryad.12jm63z8s](10.5061/dryad.12jm63z8s)

## Description of the data and file structure

This is the data for Efficient and wavelength-tunable second-harmonic generation towards the green gap.

the data include the the Fig 1, Fig 2, and Fig3.

### Files and variables

#### File: data\_green\_light\_science\_advance.zip

**Description**\
This archive contains all the data and MATLAB scripts needed to reproduce every figure in the paper, including dispersion profiles, quality‐factor (Q) traces, and all other measurement traces.

**Files & Usage**

* **Fig1.m, Fig2.m, Fig3.m**
* Each script generates one of the paper’s figures.
* All necessary raw data have been pre-integrated: simply open the script in MATLAB and run each section in order.
* In-script comments explain what each block does and the meaning of each plotted trace.
* **Data files (.fig, .mat)**
* Collected direct...,