Apparatus and method for high-efficiently tuning the wavelength of light using collimating module including an axicon lens

A method of providing a tunable wavelength light source comprising the steps of:

• irradiating diffused light with a diffuse light source;
• collimating the light irradiated from the diffuse light source with a collimating module, wherein the collimating module comprises an axicon lens;
• selecting, with an angularly tunable bandpass filter module, a specific wavelength of light by passing the light that has passed through the collimating module;
• and
• mixing, with a rod lens, a plurality of lights that has passed through the angularly tunable bandpass filter module, wherein the step of mixing comprises the step of outputting a light having a single wavelength by mixing the plurality of lights when each of the specific wavelengths of the plurality of lights passing through the angularly tunable bandpass filter module are selected differently according to an angle of incidence of each of the lights,
• wherein:
• the angularly tunable bandpass filter module is a circular plate and comprises a plurality of angularly tunable bandpass filters, wherein the plurality of angularly tunable bandpass filters are circularly disposed at the edge of the angularly tunable bandpass filter module, and the selected wavelength band of light passing through the filter is different for each of the plurality of angularly tunable bandpass filters;
• and
• the method further comprises a step of rotating an angularly tunable bandpass filter module, wherein for selection of a specific wavelength band of light, one of the plurality of angularly tunable bandpass filters is selected as the angularly tunable bandpass filter module is rotated,
• the method further comprising a step of rotating a angularly tunable bandpass filter, wherein
• each of the plurality of angularly tunable bandpass filters is rotated to adjust the angle of incidence of light to a corresponding filter, and the wavelength of light passing through the filter is selected differently depending on the angle of incidence, and
• light passes through a selected angularly tunable bandpass filter among the plurality of angularly tunable bandpass filters at a specified angle of incidence as the angularly tunable bandpass filter is rotated, so that a specific wavelength within a selected wavelength band of light is selected,
• the method further comprising a step of rotating another angularly tunable bandpass filter module facing the angularly tunable bandpass filter, wherein said another angularly tunable bandpass filter module and an angularly tunable bandpass filter of said another angularly tunable bandpass filter module are rotated, so that the bandwidth of a band having the specific wavelength within the selected wavelength band as a central wavelength is tuned.