Because the beam formed by a tapered coupler is produced by many rays that emerge at slightly different angles, the outgoing beam is characterized by a relatively large divergence. 因为尖劈耦合器形成的光束是由许多出射角稍有不同的光线组成的，放出射光束的特点是具有较大的发散度。
In addition, the circular disc refractometer can achieve quite good linearity even for non-parallel light beams. 这种圆盘型光电折射率计甚至可对非平行入射光束仍保持相当好的线性度。
