Generation of optical Y-junction Bessel beams.
A method is proposed to split the central spot of zero-order Bessel beams into two parallel spots along the propagation axis of the beam. A magnetic-liquid deformable mirror is used to provide the required phase profile combining an axicon and a phase step. The obtained Y-junction Bessel beam has been characterized; the 80 µm central spot of the Bessel beam is split into two spots of the same size that have been propagated over a length exceeding 15 cm. The observations are consistent with the predictions of a numerical model. Potential applications of Y-junction Bessel beams are discussed.