Control device, control circuit, control method, and recording medium with a control program recorded therein

The present invention provides a control device capable of performing feedback control so that a signal-wavelength input to a control target object becomes a specific signal-wavelength, using an input signal whose duty value is other than 50%. Accordingly, the control device according to the present invention is a control device for performing feedback control so that a signal-wavelength input to a control target object becomes a specific signal-wavelength, the control device including a control unit that performs feedback control so that the signal-wavelength input to the control target object becomes the specific signal-wavelength, using an input signal input to the control target object, the input signal whose duty value is other than 50%.