Abstract: A system is disclosed that allows passage of electrical signals across a rigid boundary, such as a pressure hull of a submarine or vessel that operates in water. The passages provided by acoustic means are accomplished without any holes being made in the rigid boundary.

Abstract: A method and optical system for fading-free reception of optical phase sils having temporally varying polarization, phase and phase frequency is provided. Two orthogonally polarized local oscillators light waves of different frequencies are utilized to produce optical interference with an unknown polarization state optical input signal. Square law detection of the resultant optical interference yields a composite radio frequency signal which is decoded into four electronic outputs. These outputs are temporally differentiated and cross multiplied to produce a single composite output corresponding to the phase rate of the optical input signal. The total power of the four electronic outputs is proportional to the input signal power. The present invention thus maintains constant signal to noise ratios and avoids the use of internal clippers and limiters.

Abstract: An efficient and cost effective analog telemetry system for transmitting receiving many individual data channels over long distances is provided by having each data channel signal modulate a pseudo-random number (PRN) signal which has been delayed for a distinct number of clock cycles for each data channel. The modulated PRN signals are then outputted to a single data line and summed. At the remote receiver, each data signal is recovered by cross correlating the modulated PRN signals with individual reference PRN signals. A synchronous delay generator in each data channel properly aligns each reference signal in time with its corresponding modulated PRN signal. Other modulated PRN signals, which are not aligned with the proper reference PRN signal, are rejected.

Abstract: The invention comprises a fixture and method for holding optical waveguid such as fiber optic cable, in a relatively stable fashion for processing. The fixture includes a first frame and a second frame, releasably securable to the first frame to form a unitary structure. Chambers disposed in at least one of the frames are adapted for removably receiving optical fiber cable when the first and second frames are released from one another and for securely retaining with molding material optical fiber cables when the first and second frames form the unitary structure. A process area is defined in the unitary structure such that segments of optical fiber cables secured therein are accessible in the process area for processing. An optional coating fixture is securable to said unitary structure for forming with a molding material a protective coating about the cable segments in the processing area.

Abstract: A method and apparatus for controlling polarization, as one of a pair of erdependent light characteristics of an optical fiber, in response to a time dependent signal without the introduction of any significant variation in phase delay. A pair of transducers compress the optical fiber at spaced locations. When phase of energization of a first transducer in response to the time dependent signal is 180.degree. out-of-phase with the energization of the second transducer, the polarization shifts in response to the time dependent signal without any significant shift is phase delay. When the phases are in-phase, phase delay shifts in response to the time dependent signal without any significant shift in polarization. Multiple sets of transducers disposed along the optical fiber enable smooth variation of the controlled polarization or phase delay when a first transducer in each set is angularly displaced about the optical fiber by 45.degree. with respect to a first transducer in an adjacent set.