Abstract: An embodiment of the present invention relates to a paste which includes a perfluoropolyether (A) having two or more ethylenically unsaturated bonds in the molecule, a polysiloxane (B) having two or more ethylenically unsaturated bonds in the molecule, and a radical initiator (C).

Abstract: An underwater optical communication device communicates with another underwater optical communication device. The underwater optical communication device is provided with an optical transmitter, an optical receiver, and a controller. The optical transmitter transmits laser light to another underwater optical communication device. The optical receiver receives laser light from another underwater optical communication device. The controller controls the optical transmitter and the optical receiver. The optical receiver is provided with a polarizing plate configured to transmit S-polarized light of natural light and suppress transmission of P-polarized light of natural light and a photodetector configured to detect laser light emitted from the polarizing plate.

Abstract: A light receiving device of optical communication equipment includes a condenser lens configured to condense incident light, a collimation lens having a focal length shorter than a focal length of the condenser lens, the collimation lens being configured to convert light from the condenser lens to parallel light, a bandpass filter having a filter surface on which the parallel light from the collimation lens is perpendicularly incident, the bandpass filter being configured to transmit only a wavelength of the incident light, and a light receiving element configured to detect light transmitted through the bandpass filter.

Abstract: An optical fiber laser module is provided with an optical fiber (2) for diffusing light, and a laser module housing (1) connected to the optical fiber. The laser module housing is provided with a laser light source (11) that outputs laser light to the optical fiber, and a light detector (14) that detects laser light that has been wave-guided through the full length of the optical fiber. The optical fiber is provided with: a light incident part (3a) provided inside the laser module housing, laser light from the laser light source being incident on the light incident part; and a terminal part (3) on which is formed a reflective film (4) that reflects the laser light that was incident on the light incident part and was wave-guided through the full length of the optical fiber so as to return the laser light to the light incident part.

Abstract: An underwater laser source is used in water and comprises a water pressure-resistant cylinder A having a light emission window 4, and the water pressure-resistant cylinder A comprises a plurality of semiconductor lasers 11a-11f, and converging lens 13 that converges each laser light from the plurality of semiconductor lasers 11a-11f, and emits converged each laser light to the light emission window 4.

Abstract: An underwater laser source is used in water and comprises a water pressure-resistant cylinder A having a light emission window 4, and the water pressure-resistant cylinder A comprises a plurality of semiconductor lasers 11a-11f, and converging lens 13 that converges each laser light from the plurality of semiconductor lasers 11a-11f, and emits converged each laser light to the light emission window 4.

Abstract: An optical fiber laser module is provided with an optical fiber (2) for diffusing light, and a laser module housing (1) connected to the optical fiber. The laser module housing is provided with a laser light source (11) that outputs laser light to the optical fiber, and a light detector (14) that detects laser light that has been wave-guided through the full length of the optical fiber. The optical fiber is provided with: a light incident part (3a) provided inside the laser module housing, laser light from the laser light source being incident on the light incident part; and a terminal part (3) on which is formed a reflective film (4) that reflects the laser light that was incident on the light incident part and was wave-guided through the full length of the optical fiber so as to return the laser light to the light incident part.

Abstract: The optical connector includes an insert-opening 3b into which the optical fiber 4 is inserted, a connection-opening 3a that positions the tip of the optical fiber inserted into an insert-opening to a desired laser light connection position, and a guide 2a that guides the optical fiber inserted into the insert-opening 3f, where the insert-opening is in-place on the non-optical-axis of the laser light to be connected and a position-difference between the connection-opening and the insert-opening is larger than the predetermined value.