Optical transmission/reception module

An optical transmission/reception module, comprising:

• a light-emitting element to emit transmission light;
• a first lens holder to support a first lens which collimates the transmission light which has left the light-emitting element;
• a first partial wave filter to pass therethrough the transmission light collimated by the first lens;
• a second lens holder to support a second lens which gathers the light, which has passed through the first partial wave filter, at an end surface of an optical fiber;
• a second partial wave filter to subject a first reception light beam and a second reception light beam having different wavelengths to a partial wave formation operation after the first and second reception light beams emitted from the end surface of the optical fiber have been collimated by the second lens and reflected by the first partial wave filter;
• a third lens holder to support a third lens which gathers and concentrates the first reception light beam subjected to the partial wave formation operation by the second partial wave filter;
• a first light-receiving element to receive the light gathered and concentrated by the third lens;
• a first housing block accommodating the light-emitting element, first lens holder and first lens, the first and second partial wave filters, the second lens holder and second lens, the third lens holder and third lens, the first light-receiving element;
• a fourth lens holder to support a fourth lens which gathers and concentrates the second reception light subjected to the partial wave formation operation by the second partial wave filter;
• a second light-receiving element to receive the light gathered and concentrated by the fourth lens;
• and
• a second housing block mounted to the first housing block and accommodating the fourth lens and fourth lens holder and the second light-receiving element and comprising a fourth passage to guide the second reception light beam which has passed through the second partial wave filter to the fourth lens, with the fourth passage being used in common by the first housing block;
• the first housing block further comprising:
• a first passage to guide the transmission light collimated by the first lens to the first partial wave filter;
• a second passage to guide the transmission light which has passed through the first partial wave filter to the end surface of the optical fiber through the second lens, and to guide the reception light which has been emitted from the end surface of the optical fiber to the first partial wave filter through the second lens;
• a third passage to guide the first reception light beam reflected by the first partial wave filter to the third lens;
• a first mounting surface, disposed between the first and second passages, to mount the first partial wave filter thereon;
• a first cutout formed from an outside surface of the first housing block to the first mounting surface and to a side thereof such that the first partial wave filter is transportable from outside the first housing block through the first cutout and directly mountable on the first mounting surface;
• a second mounting surface, disposed between the third and fourth passages, to mount the second partial wave filter thereon;
• and
• a second cutout formed from an outside surface of the first housing block to the second mounting surface and to a side thereof such that the second partial wave filter is transportable from outside the first housing block through the second cutout and directly mountable on the second mounting surface.