# Optical-controlled wavelength-tunable Q-switched mode-locked fiber laser based on graphene-deposited micro-FBG

## TL;DR

This paper presents a compact, optically tunable fiber laser that uses graphene-coated micro-FBG for precise wavelength control, enabling stable Q-switched mode-locking with potential applications in optical computing and microwave generation.

## Contribution

It introduces a novel graphene-coated micro-FBG device for optical wavelength tuning in a fiber laser, demonstrating precise control and stable mode-locking.

## Key findings

- Wavelength can be tuned from 1550.1 nm to 1551.9 nm
- Linear sensitivity of 6.3 pm/mW for wavelength tuning
- Stable Q-switched mode-locked pulses achieved

## Abstract

We report a wavelength-tunable Q-switched mode-locked fiber laser based on a compact optical tuning device, which is fabricated by coating single-layer graphene on the surface of micro-fiber Bragg grating (MFBG). Based on thermal-optical effect through evanescent interaction between graphene and MFBG, the center wavelength of MFBG can be accurately controlled by adjusting power of an external laser. By inserting the fabricated device into a compact fiber laser cavity mode-locked by single-wall carbon nanotubes, stable Q-switched mode-locked pulse is generated. Experimental results show that the wavelength can be precisely optical-tuned from 1550.1 nm to 1551.9 nm with a linear sensitivity of 6.3 pm/mW. Such an optical-controlled wavelength-tunable Q-switched mode-locked fiber laser may find potential applications in all-optical computing, all-optical logic gating and generation of microwave source.

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Source: https://tomesphere.com/paper/1704.06391