Ultrafast Optical Switches and Wavelength Division Multiplexing (WDM) Amplifiers Based on Bismuth Oxide Glasses

Glasses with a high refractive index exhibit interesting properties. All optical switching and broadband amplification performances have been demonstrated using glasses based on bismuth oxide (Bi 2 O 3 ). Optical Kerr shutter (OKS) switching and degenerated four‐wave mixing experiments for nonresonant‐type Bi 2 O 3 –B 2 O 3 –SiO 2 glasses have been performed using femtosecond lasers. This glass exhibits an ultrafast response (<150 fs) in OKS operation. Moreover, terahertz‐range (THz‐range) optical switching has been successfully performed with this glass, using a 1.5‐THz pulse train. Erbium‐doped bismuth‐based oxide glasses also have been prepared for wavelength division multiplexing (WDM) amplifiers. These glasses exhibit broadband emission and negligible concentration quenching, which indicates that the bismuth‐based glass is suitable for broadband amplifiers and highly doped short‐length fiber applications for metro use.