Silver Nanowires with Ultrabroadband Plasmon Response for Ultrashort Pulse Fiber Lasers

Abstract

Broadband and ultrafast response of plasmonic nanoparticles offer a significant advantage in optical modulation and allow ultrashort pulse generation from visible to mid‐infrared (MIR) region. However, many of the materials exhibit limited saturable absorption bandwidth in MIR spectral region, which limits the MIR pulses generation and the relative applications. Herein, it is shown that solution‐processed silver nanowires (AgNWs) exhibit an ultrabroadband localized surface plasmon resonance (LSPR) from 0.3 to over 25 μm, which contributes to wideband nonlinear optical response in the whole MIR region. Using those AgNWs as saturable absorbers (SA), all‐optical modulation in near infrared and MIR region is demonstrated. Mode‐locked lasers are realized at 1, 1.5, and 2 μm bands with minimal pulse duration down to a few hundreds of femtoseconds, and a Q‐switched laser at 3 μm band is achieved. The results show that AgNWs SA has the potential for constructing pulsed lasers in the MIR or even longer wavelength region.

Keywords

• localized surface plasmon resonances
• saturable absorbers
• silver nanowires
• ultrabroadband nonlinear optical responses
• ultrashort pulse fiber lasers