Spectral device with enhanced stability of optical sensor and operating method thereof

A spectral device comprising:

• a light splitter configured to split an incident light into a reference light and a signal light;
• one beam shutter configured to perform control for selectively outputting either the reference light or the signal light and for blocking the two lights together;
• and
• a controller configured to provide an absorption property of a bio-material by comparatively quantizing an intensity of the reference light and an intensity of the signal light, which are received into a sensor through the beam shutter,
• wherein the beam shutter is further configured to completely block a light from entering the sensor by blocking both a beam path of the reference light and a beam path of the signal light for a predetermined time,
• wherein the beam shutter comprises a physical shutter that is mounted on a rail capable of linear movement and is capable of iteratively moving a specific distance, and
• wherein the physical shutter has a hole of a beam block, which the signal light passes through, and a hole of a beam block, which the reference light passes through, formed asymmetrically with respect to a center line of the physical shutter, wherein the physical shutter moves linearly from side to side, allowing the signal light and the reference light to sequentially pass through their corresponding holes.