Wavelength-tunable liquid crystal etalon filter, light source and optical transceiver including the same

A wavelength tunable etalon filter through which only incident light with a predetermined wavelength band is transmitted among incident light, wherein the wavelength tunable etalon filter comprises:

• a pair of substrates;
• a pair of high reflection layers;
• liquid crystal configured to be injected between the pair of substrates;
• an internal seal line configured to be formed between the pair of substrates to maintain a gap between the pair of substrates or the pair of high reflection layers, have a sub inlet through which the liquid crystal is discharged, and have a main accommodating space configured to have a predetermined shape around an area L-through which light is incident or passed;
• an external seal line configured to be formed between the pair of substrates, have a predetermined shape, and is positioned outside the internal seal line to form a sub accommodating space outside the internal seal line;
• and
• an encapsulant configured to seal the main accommodating space to prevent discharge of the liquid crystal,
• wherein a gas accommodating space in which gas exists is formed in the sub accommodating space, and the gas accommodating space includes a non-liquid crystal chamber having a relatively wider width than an area adjacent to the non-liquid crystal chamber at a predetermined location and having a step difference from a peripheral portion, thereby minimizing re-discharge of gas introduced into the sub accommodating space to outside of the sub accommodating space.