在二阶非线性介质中观察到二维多色阵列辐射.空间分布为椭圆状的飞秒光束在二阶非线性介质中空间分裂成二阶空间孤子,与另一飞秒光束交叉重叠发生非共线级联二阶非线性耦合后产生了二维多色阵列辐射.同时,交叉耦合的光束在介质中形成了瞬态光栅,同步注入的超连续白光被此瞬态光栅衍射,获得相同相位的上转换二维多色阵列放大.注入少量二次谐波,抑制了二阶空间孤子的产生,从而导致二维多色阵列辐射及其上转换放大被抑制.
Two-dimensional multicolored transverse arrays were demonstrated experimentally for the first time in a quadratic nonlinear medium. Cascaded noncollinear quadratic processes took place between input pulses and quadratic spatial solitons formed by spatial breakup of one of the pump beams with small ellipficity. Two-dimensional multicolored transverse arrays as well as transient grating were formed by cascaded noncollinear quadratic processes. Synchronously seeded supercontinuum pulses were diffracted and amplified, resulting in two-dimensional multicolored up-conversion parametric amplification. These two kinds of two-dimensional patterns were readily suppressed by seeding with weak second harmonic pulses in one of the pump pulses.