An optical transceiver comprising: a coupling assembly ; and a condensing assembly , wherein the coupling assembly comprises a first surface and a second surface that are oppositely disposed and wherein multiple first lenses are disposed on the first surface ; the condensing assembly comprises a fastener , multiple filters , a reflector , and a light passing region ; the fastener comprises a third surface and a fourth surface that are oppositely disposed; the multiple filters and the light passing region are disposed on the third surface ; the light passing region is located on a side of the multiple filters ; the reflector is disposed on the fourth surface ; the condensing assembly is fastened to the second surface ; the multiple filters are optically aligned with the multiple first lenses separately; each of the multiple filters comprises a pair of light outgoing/incoming surfaces and a pair of side surfaces ; the pair of side surfaces are connected between the pair of light outgoing/incoming surfaces ; the pair of light outgoing/incoming surfaces are separately attached to the second surface and the third surface 211); the side surfaces of each of the multiple filters are perpendicular to the first surface ; the coupling assembly is configured to receive light of different wavelengths; and the light of different wavelengths enters the fastener through the multiple filters and is multiplexed or demultiplexed by the reflector and the multiple filters , and multiplexed or demultiplexed light enters the coupling assembly through the light passing region ; characterised in that an angle is formed between the second surface and the first surface , wherein a range of the angle between the first surface and the second surface is from 6° to 13°; and in that the major axis of each of the multiple first lenses is perpendicular to the first surface . a coupling assembly ; and a condensing assembly , wherein the coupling assembly comprises a first surface and a second surface that are oppositely disposed and wherein multiple first lenses are disposed on the first surface ; the condensing assembly comprises a fastener , multiple filters , a reflector , and a light passing region ; the fastener comprises a third surface and a fourth surface that are oppositely disposed; the multiple filters and the light passing region are disposed on the third surface ; the light passing region is located on a side of the multiple filters ; the reflector is disposed on the fourth surface ; the condensing assembly is fastened to the second surface ; the multiple filters are optically aligned with the multiple first lenses separately; each of the multiple filters comprises a pair of light outgoing/incoming surfaces and a pair of side surfaces ; the pair of side surfaces are connected between the pair of light outgoing/incoming surfaces ; the pair of light outgoing/incoming surfaces are separately attached to the second surface and the third surface 211); the side surfaces of each of the multiple filters are perpendicular to the first surface ; the coupling assembly is configured to receive light of different wavelengths; and the light of different wavelengths enters the fastener through the multiple filters and is multiplexed or demultiplexed by the reflector and the multiple filters , and multiplexed or demultiplexed light enters the coupling assembly through the light passing region ; characterised in that an angle is formed between the second surface and the first surface , wherein a range of the angle between the first surface and the second surface is from 6° to 13°; and in that the major axis of each of the multiple first lenses is perpendicular to the first surface . <EOS>