1 x N fibre coupler employing diffractive optical element

A new broadband 1 x N fibre coupler has been developed which employs diffra ctive optical elements (DOEs). The fibre coupler consists of an input fibre collimator, two aspherical lenses, a specially designed DOE and arrayed ou tput fibres. The demonstrated 1 x 8 fibre coupler has a low polarisation de pendent loss of less than or equal to 0.05dB, an excess loss of less than o r equal to 2.4dB, and good uniformity of +/- 0.25dB over a broad wavelength range of 1510-1570nm.