Ionic Liquid Gated Carbon Nanotube Saturable Absorber for Switchable Pulse Generation

Abstract

Materials with electrically tunable optical properties offer a wide range of opportunities for photonic applications. The optical properties of the single-walled carbon nanotubes (SWCNTs) can be significantly altered in the near-infrared region by means of electrochemical doping. The states’ filling, which is responsible for the optical absorption suppression under doping, also alters the nonlinear optical response of the material. Here, for the first time we report that the electrochemical doping can tailor the nonlinear optical absorption of SWCNT films and demonstrate its application to control pulsed fiber laser generation. With a pump–probe technique, we show that under an applied voltage below 2 V the photobleaching of the material can be gradually reduced and even turned to photoinduced absorption. Furthermore, we integrated a carbon nanotube electrochemical cell on a side-polished fiber to tune the absorption saturation and implemented it into the fully polarization-maintaining fiber laser. We show that the pulse generation regime can be reversibly switched between femtosecond mode-locking and microsecond Q-switching using different gate voltages. This approach paves the road toward carbon nanotube optical devices with tunable nonlinearity.

Generating Picosecond Pulses With the Largest Number of Lasing Wavelengths by an All-Fiber Optical Parametric Oscillator

“…The mode-locked erbium-doped fiber laser was designed to generate picosecond laser pulses at 1550 nm band. It has a ring cavity structure and utilizes single wall carbon nanotube (SWNT) film as a saturable absorber [11,12]. A segment of erbium-doped fiber (EDF) is used as the gain medium, and pumped by a 976 nm laser diode (LD) through a 980/1550 nm wavelength division multiplexer (WDM).…”

Carbon nanotube mode-locked fiber lasers: recent progress and perspectives

“…It is well known that the electronic performance of CNT is superior. The recent demonstration of electric-controlled versatile pulse generation through a gated CNT film shows strong optoelectronic capability [304]. Moreover, well-aligned CNT samples based on various methods feature strong polarization-dependent optical absorption.…”

Electro-optically gated in-line saturable absorbers for fibre lasers

“…Several recent publications [9][10][11][12][13] are dedicated to research into ways of dynamic modification by electric field or optical radiation of parameters of saturable absorbers made either with carbon nanotubes or noncarbon materials. Dynamic adjustment of saturable absorber parameters not only allows variation of the laser generation regime, but may also lead to a variety of generation regimes, thus providing a possibility of controllable switching between such different regimes.…”