An optical connector including a first optical fiber having a first diameter and having a core that includes a thermally expanded core portion adjacent a first end of the first optical fiber, a second optical fiber spliced to a second end of the first optical fiber, the second optical fiber having a second diameter less than the first diameter, and a connector bore having a first bore portion configured to receive the first end of the first optical fiber.

A passive microscopic flow sensor includes a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fiber. The three-dimensional microscopic optical structure includes a post attached off-center to and extending longitudinally from the cleaved tip of the optical fiber. A rotor of the three-dimensional microscopic optical structure is received for rotation on the post. The rotor has more than one blade. Each blade has a reflective undersurface that reflects a light signal back through the optical fiber when center aligned with the optical fiber, the blades of the rotor shaped to rotate at a rate related to a flow rate.

Various embodiments of the teachings herein include a pulse counter for fluid pressure changes. The pulse counter may include: a first and a second housing part with a fluid passage; a circuit board at least partially enclosed within the housing, the circuit board comprising a light pulse transmitter and a light pulse receiver; a battery at least partially within the housing, the battery supplying electric power to the light pulse transmitter and the light pulse receiver; a rod slidably arranged within the housing, with one end of the rod within the fluid passage, and a second end arranged at least partly breaking a light pulse between the light pulse transmitter and the light pulse receiver; and a spring forcing the rod away from the light pulse and towards the fluid passage.

Various embodiments of the teachings herein include a pulse counter for fluid pressure changes. The pulse counter may include: a first and a second housing part with a fluid passage; a circuit board at least partially enclosed within the housing, the circuit board comprising a light pulse transmitter and a light pulse receiver; a battery at least partially within the housing, the battery supplying electric power to the light pulse transmitter and the light pulse receiver; a rod slidably arranged within the housing, with one end of the rod within the fluid passage, and a second end arranged at least partly breaking a light pulse between the light pulse transmitter and the light pulse receiver; and a spring forcing the rod away from the light pulse and towards the fluid passage.

A haptic sensing device, including a light source, an optical waveguide, a photoelectric sensor, and a housing. The optical waveguide includes a waveguide layer and a cladding, the cladding encloses the waveguide layer, and a refractive index of the waveguide layer is greater than a refractive index of the cladding. The waveguide layer includes a plurality of paths, the light source is disposed at an input end of each path, and the photoelectric sensor is disposed at an output end of each path. The light source, the optical waveguide, and the photoelectric sensor are accommodated in the housing. A plurality of contacts are distributed on the housing. When a contact is pressed, the contact is in contact with one path, and the path is deformed. When any two contacts are pressed, the two contacts are in contact with different paths.

A sensor. In some embodiments, the sensor includes a first waveguide, a flexible support element, and a second waveguide. A first portion of the first waveguide may be supported by the flexible support element and separated by a first gap from a second portion of the first waveguide. The flexible support element may be capable of bending so as to cause an effective index of refraction of the first waveguide to change. The first waveguide may be coupled to the second waveguide through a second gap, the second gap being at an end of the first waveguide and an end of the second waveguide.

A water pressure fluctuation measuring system detects a water pressure fluctuation. A cable, which includes an optical fiber, is provided on or in the ground of the seabed in such a way that the optical fiber is expanded and contracted according to the water pressure fluctuation. An optical output unit outputs monitoring light to the optical fiber. A partial reflection unit is provided on a path of the optical fiber in the cable and partially reflects the monitoring light. An optical reception unit receives reflection light reflected by the partial reflection unit. A calculation unit measures a length of the optical fiber to the partial reflection unit, based on a round-trip propagation time of the received reflection light, and monitors a change of the length over time.

A water pressure fluctuation measuring system detects a water pressure fluctuation. A cable, which includes an optical fiber, is provided on or in the ground of the seabed in such a way that the optical fiber is expanded and contracted according to the water pressure fluctuation. An optical output unit outputs monitoring light to the optical fiber. A partial reflection unit is provided on a path of the optical fiber in the cable and partially reflects the monitoring light. An optical reception unit receives reflection light reflected by the partial reflection unit. A calculation unit measures a length of the optical fiber to the partial reflection unit, based on a round-trip propagation time of the received reflection light, and monitors a change of the length over time.

A measuring device for pore throat pressure of Jamin effect based on mechanochromic materials is provided and includes: a bubble pressurization part, configured to inject bubbles into a microscopic visualization test part; the microscopic visualization test part including a mechanochromic material and a pore throat structure, configured to characterize changes of pore throat pressure during bubble injection; a waste liquid recycling part, configured to recycle bubble waste liquid passing through the microscopic visualization test part; a data acquisition and analysis part, configured to acquire changing data of the pore throat pressure in the microscopic visualization test part and analyze the changing data to obtain the pore throat pressure. The device is simple in structure and easy to operate, and provides a method for measuring an internal surface pressure of an object. The method can realize a real time measurement of the pore throat pressure of Jamin effect.

The invention relates to a method for in-life testing of the formation of the solid electrolyte interface layer of a battery cell, comprising the following steps: sensing the temperature within the battery cell, recording a first set of temperature (T) and/or pressure data related to the temperature variation (ΔT) and/or pressure variation within the battery cell over a first charge of the battery cell, and determining a positive or negative datum relating to the formation of solid electrolyte interface layer of the battery cell according to said first set of temperature and/or pressure data