The spectral responses of the µIMZI during its initial testing were measured in possibly wide wavelength range, i.e., from 1100 to 1700 nm, using Yokogawa AQ6370B optical spectrum analyzer and Leukos SM30 supercontinuum white light laser source. The RI sensitivity was measured by immersing the sensors in glycerine/water solutions with RI in the range nD=1.33300-1.40100 RIU. The nD of the solutions was determined using Rudolph J57 automatic refractometer. The transmission measurements were conducted at constant mechanical tension and temperature (25 °C).