the same way as in when attenuation factor is a parameter and as a result an aperture having a desired diameter is formed by plastic deformation or breakage of the tip this method is mainly used with straight type optical fiber probes it is also possible to apply this method to bent type optical fiber probes and cantilevers with a microscopic aperture here in the case of a straight type optical fiber probe an amount of vibration of the probe is monitored while in the case of a bent type optical fiber probe or a cantilever having a microscopic aperture a twisting angle is monitored fig1 shows a force curve in the case of bringing a probe and a sample together while vibrating the probe within a plane parallel to the sample surface the horizontal axis represents a distance between the sample and the probe with movement to the left being a condition of the probe and the sample approaching each other the vertical axis represents a vibration attenuation factor compared to an initial vibration state of the optical fiber probe or compared to vibration of the twisting angle in the case of a bent type optical fiber probe or a cantilever having a microscopic aperture with 0 being a.