Wavelength separation optical device and multiple wavelength light transmission module

A multi wavelength optical signal module comprising:

• a coupling portion with an optical signal transmission use optical fiber;
• a wavelength separation optical device;
• a photo detector array;
• and
• a signal receiving circuit which amplifies signals from the photo detector array and waveshapes the same, wherein the coupling portion and the wavelength separation optical device are connected by a multi mode optical fiber, the wavelength separation optical device includes a spreading angle reducing means which reduces the spreading angle of the incident optical signals from the multi mode optical fiber and a front polarized light conversion means which converts the incident optical signals from the incident portion into linear polarized light, and the optical signals converted into linear polarized light by the front polarized light conversion means are made incidence into a wavelength separation means in the wavelength separation optical device to separate the same for every wavelength.

A multi wavelength light transmission module comprising:

• a coupling portion with an optical signal transmission use optical fiber;
• a wavelength separation optical device;
• a photo detector array;
• a signal receiving circuit which amplifies signals from the photo detector array and waveshapes the same;
• a light source array;
• a signal transmission circuit which drives the light source array;
• and
• a wavelength joining device which joins optical signals from the light source array;
• wherein the coupling portion and the wavelength separation optical device are connected by a multi mode optical fiber, the wavelength separation optical device includes a spreading angle reducing means which reduces the spreading angle of the incident optical signals from the multi mode optical fiber and a front polarized light conversion means which converts the incident optical signals from the incident portion into linear polarized light, and the optical signals converted into linear polarized light by the polarized light conversion means are made incidence into a wavelength separation means in the wavelength separation optical device to separate the same for every wavelength.