Low-loss lens connector for single-mode fibers

A compact (plug = 1.5 g) low-loss lens connector for single-mode fibers (SMF) which can operate in a wide range of wavelengths was developed. This lens connector consists of two lens assemblies using 250-microm diam AR coated sapphire balls precisely positioned between the SMF endfaces. The lens connection loss between the same kind of SMFs with a Gaussian beam spot radius ranging from 3.55 to 6.63 microm is predicted to be < or =1.0 dB. The average lens connection loss is 0.54 dB. Loss reproducibility after connecting 1000 times is less than or equal to +/-0.15 dB.