“…So far, several generic types of photorefractive spatial solitons have been investigated, namely, quasi-steady-state soliton [2,3], screening soliton [4,5], photovoltaic soliton [6,7], and screening-photovoltaic soliton [8], all of which evolve from a nonlinear change in the refractive index of a material induced by the light intensity distribution. Very recently, a new type of spatial solitons, photoisomerization polymer solitons (PPSs) were predicted theoretically in 2004 [9], and were subsequently verified theoretically [10,11] and experimentally [12,13] by using linearly and circularly polarized light in photoisomerization polymer.…”