Abstract: There is provided a wavelength determining device including a reference wavelength measuring section 42 that, based upon a number A of interference fringes generated by an optical path difference of first reference wavelength light (wavelength: ?1) and a number C of interference fringes generated by the optical path difference of second reference wavelength light (wavelength: ?2), measures the wavelength of the second reference wavelength light, an input light wavelength measuring section 44, based upon the number A of the interference fringes generated by the optical path difference of the first reference wavelength light (wavelength: ?1) and a number B of interference fringes generated by the optical path difference of input light (wavelength: ?x), measures the wavelength of the input light, a correction coefficient determining section 46 that determines a second correction coefficient k based upon the measured wavelength ?c of the second reference wavelength light and the measured wavelength ?m of the inpu

Abstract: A temperature stabilizer for accurately stabilizing the temperature of an object is provided. The temperature stabilizer stabilizes the temperature of an object to a reference temperature. The temperature stabilizer includes an oscillator provided in proximity to the object, for generating an oscillation signal having a frequency corresponding to an inputted frequency control signal, a phase detector for detecting the phase difference between a feedback signal based on the oscillation signal and a reference clock signal having a predetermined frequency, a loop filter for generating the frequency control signal to synchronize the feedback signal with the reference clock signal based on the output from the phase detector, a comparator for comparing the value of the frequency control signal with a reference value determined corresponding to the reference temperature and an electric heating converter for heating or cooling the object based on the comparison result from the comparator.