Optofluidic Chip of a Single-Mode Fiber Variable Optical Attenuator

An optofluidic chip of the single-mode fiber variable optical attenuator (VOA) is proposed. This chip has a simple structure, and it utilizes microfluid and air to regulate the optical attenuation, where air acts as a shutter. Here, the single-mode characteristics of the VOA chip are discussed at 1310 nm and 1550 nm. The experiment results indicate that it is feasible to regulate optical attenuation using the proposed chip. The VOA with this chip has a large optical attenuation range (82 dB) and a very wide operation waveband from visible to near infrared wavelengths. The measured insertion loss is 0.68 dB at 1310 nm and 0.92 dB at 1550 nm, and the measured return loss is 47.8 dB at 1310 nm and is 47.67 dB at 1550 nm.