Achromatic optical subassembly

An achromatic optical subassembly, suitable for connecting with an optical fiber, the achromatic optical subassembly including:

• a light-emitting unit, including a light source with broad spectral width, wherein the spectral width of the light source with broad spectral width is at least greater than 30 nm;
• a light guide unit, disposed opposite the light-emitting unit, the light guide unit including a ferrule for the optical fiber to pass through;
• and
• an achromatic unit, disposed between the light-emitting unit and the guide unit, wherein the achromatic unit includes a first lens and a second lens, the first lens is disposed between the light-emitting unit and the light guide unit and has positive refractive power, a light entrance side surface of the first lens is convex, a light exit side surface of the first lens is convex, the second lens is disposed between the first lens and the light guide unit and has negative refractive power, a light entrance side surface of the second lens is concave, a light exit side surface of the second lens is convex;
• wherein the light source with broad spectral width passes through the achromatic unit, after which the different wavelengths of the light source with broad spectral width traveling along the respective optical paths are brought to the same focus and incident on the optical fiber in the light guide unit.