Hewlett-packard Company

Agilent Technologies, Inc.

David K Donald

Leslie Ann Field

Phillip W Barth

Storrs Townsend Hoen

Julie Elizabeth Fouquet

Hong Lin

Jonathan D Servaites

Wayne V Sorin

Kok Wai Chang

Kok-Wai Chang

John L Vaught

Shih-Yuan Wang

David M Bloom

Jonah Alexander Harley

Naoto A Kawamura

John D Meyer

Dale W Schroeder

Stefano Schiaffino

Long Yang

Datong Chen

William R Trutna, Jr

Mark Andrew Troll

Eric G Hanson

Shalini Venkatesh

Howard H Taub

Tirumala R Ranganath

Frank L Cloutier

Channing R Robertson

Steven A Newton

Michael J Lee

Frank K David

An apparatus and a method for controlling transmissions over an optical signaling network include one or more traffic detectors that are connected to an optical switch to receive incidentally reflected light when the switch is in a transmissive state. The switch is in the transmissive state when a fluid fills a fluid-manipulable chamber, but is in a reflective state when the chamber is free of fluid. The apparatus includes two inputs and two outputs. Typically, the inputs and outputs are waveguides having an index of refraction which approximates the index of refraction of the fluid. The traffic detectors monitor light which is incidentally reflected at interfaces of the waveguides with the chamber. Under fault-free conditions in which signal transmissions are detected to be normal, a first input is connected to a first output and a second input is connected to a second output. However, when a fault condition is detected, the two inputs exchange outputs by reversing the state of the optical switch. In the preferred embodiment, the fault-free condition is one in which the switch is in the reflective state. However, the reflective state is disabled and the transmissive state is established if a fault condition is detected. A prolonged absence of signal transmissions along one of the inputs is indicative of a fault condition. With the switch in the transmissive state, incidentally reflected light is monitored to detect a return to the fault-free condition. The outputs are again exchanged upon recognition of the fault-free condition. Optionally, the outputs are monitored to detect reverse driven &ldquo;request for resumption&rdquo; signals, and the reflective state is established if reverse driven signals are detected on both outputs, regardless of the indication of a fault along one or both of the inputs. In a second embodiment, the fault-free condition establishes a transmissive state, with incidentally detected light being monitored to determine if a fault condition requires a change to the reflective state.

Single site for healing dual optical rings

A thermally-activated gas extraction device that comprises a bubble capture chamber, an exhaust manifold, a tapered extraction chamber and an extraction heater associated with the tapered extraction chamber. The tapered extraction chamber extends from the bubble capture chamber towards the exhaust manifold and has a cross-sectional area that increases towards the exhaust manifold. A gas removal method in which the gas extraction device is provided, a bubble of gas is accumulated in the bubble capture chamber, a portion of the liquid in the tapered extraction chamber heated to nucleate a bubble of vapor, and the bubble of vapor is heated to explosively expand the bubble of vapor into contact with the walls of the tapered extraction chamber and into contact with the bubble of gas to form a composite bubble. Contact with the walls of the tapered extraction moves the composite bubble towards the exhaust manifold. Finally, heating of the composite bubble is discontinued to condense the vapor in the composite bubble.

Gas extraction device for extracting gas from a microfluidics system

A switching device for controlling fluid motion. The device includes a capillary filled with a first fluid into which a wall-confined bubble of a second fluid is introduced to achieve a first switching event. Capillary geometry and wetting properties provide a pressure-related asymmetric energy potential distribution for controlling the flow of the bubble, and the device is called an asymmetric bubble chamber, or ABC. The bubble is initially trapped in an energy potential well, and upon increase of its volume moves from the well into a region of low energy potential to achieve a second switching event. The first switching event may be blocking of a fluid channel or reflection of an optical beam in an optical crosspoint switch, while the second switching event may be unblocking of a fluid channel or restoration of transmission of an optical beam. The increase in bubble volume between the first and second switching events can act as the stroke of a fluidic piston to pump a volume the first fluid within the capillary. The device can be employed to thermally degas a liquid. The use of large-magnitude geometry-related energy potentials permits rapid cyclical operation of the device in a manner resistant to mechanical shock.

Capillary fluid switch with asymmetric bubble chamber

An optical switch that is constructed on a substrate having first and second waveguides that intersect at a gap having a predetermined width. The first and second waveguides are positioned such that light traversing the first waveguide enters the second waveguide when the gap is filled with a liquid having a first index of refraction. The gap is part of a trench in the substrate having a first region that includes the gap and a second region adjacent to the first region. The second region has a width greater than the width of the first region. A liquid having the first index of refraction is disposed in the first region. The liquid generates a gas when heated to a predetermined temperature. A first heater is disposed in the first region for heating the liquid to the predetermined temperature thereby generating a gas bubble in the liquid at the gap. Light traversing the first waveguide is reflected by the gap when the gap is filled with a gas. To change the switch into the non-reflecting state, the bubble is displaced to the second region of the trench, in response to a control signal. The displacement mechanism can be constructed from a second heater having a portion thereof located in the first region between the first heater and the second region. The displacement mechanism can also be constructed from a mechanism that applies a pressure differential across the first region thereby causing the bubble to partially extend into the second region. A third waveguide having an end terminating on the trench can also be included in the optical switch. The third waveguide is positioned such that light traversing the first waveguide enters the third waveguide when the gap is not filled with liquid.

Total internal reflection optical switch

A gas or liquid detector that includes a capacitative sensor and a capacitance detector. The capacitative sensor includes a first electrode and a second electrode separated from one another, and additionally includes Debye elements extant in the liquid adjacent such portions of the electrodes that are in contact with the liquid. The Debye elements each include a Debye capacitor with an associated shunt conductor. The shunt conductor has an exponentially-increasing conductance versus voltage characteristic. The Debye element adjacent the first electrode and the Debye element adjacent the second electrode are connected in series by conduction through the liquid. The Debye element adjacent at least the first electrode has a substantially greater capacitance than the capacitance between the electrodes absent the Debye elements. The capacitance detector is connected to the capacitative sensor and measures the capacitance of the capacitative sensor by applying an alternating voltage between the electrodes. The alternating voltage has a voltage amplitude less than the voltage amplitude at which the Debye element extant adjacent at least the first electrode ceases to be predominantly capacitative. By measuring the capacitance of the capacitative sensor using an alternating voltage having a voltage amplitude less than the voltage amplitude at which the Debye element ceases to be predominantly capacitative, the capacitances measured are one or more orders of magnitude greater than the capacitances conventionally measured between electrodes in contact with a liquid.

High output capacitative gas/liquid detector

A thermal optical switching cell has a channel of either gas or boilable liquid that crosses an optical waveguide at a forty-five degree angle. Two or more appropriately placed heaters use the water/steam/dry states of thermal ink jet technology to quickly insert, or extract, boilable liquid respectively into, or from, the channel. The boilable liquid has an index of refraction close to that of the guide. In the wet state, the channel contains the liquid and nearly all the light of the incoming guide traverses the liquid along the axis of the guide. In the dry state, the channel contains gas. Total internal reflection (TIR) occurs and light is directed at right angles away from the axis of the incoming channel. Adding a second waveguide, perpendicular to, and intersecting the first waveguide at the channel, forms a cross-bar switch. These liquid switching cells toggle between the wet and dry states. No power is required to hold the switch in the most recent state. A monitoring signal is described that can be used to determine the state of the switch. The dry state of these cells is totally internally reflecting. The wet state, however, is transmissive with a small, but objectionable, amount of reflection. A push-pull optical circuit is formed using paired cells and at least one TIR mirror. One of the cells of the circuit is always in the TIR state to provide good isolation. This circuit has the property of reporting the state of the switch-pair so that a fault can be detected. If a fault is detected, repeated activation pulses can be applied to force liquid into the correct places to maintain proper operation of the circuit.

Thermal optical switches for light

The crosstalk-inhibiting arrangement is used on a switching cell in which an optical signal from an input waveguide is alternatingly directed to first and second output waveguides, depending upon whether there is fluid in a region between the input waveguide and the first output waveguide. The fluid has a refractive index selected to promote propagation of light energy through the fluid. However, in the absence of fluid, the light is reflected toward a second switching mechanism via an intermediate waveguide. The intermediate waveguide is at an angle greater than 90&deg; relative to the input waveguide. The second switching mechanism is also fluid-manipulable and is used to inhibit leakage reflection from passing to the second output waveguide. Preferably, the angle between the intermediate waveguide and the input waveguide is in the range of 95&deg; to 150&deg;.

Non-perpendicular optical paths for a crosstalk-inhibiting switching arrangement

An improved optical switch allows for the testing, calibration and monitoring of optical switch points in an optical switching matrix. A test column and a test row of additional switch elements and optical paths enable the improved optical switch to provide testing, calibration and monitoring of each optical switch point in the optical switch matrix using a test input source and a test output receiver. The improved optical switch may also be used to test for the presence of light at any input and to inject a test signal into the matrix in order to test for the presence and quality of light at any output.

Optical switch having test ports

A bubble valve that comprises a liquid delivery channel and a localized heating arrangement. The liquid delivery channel includes an upstream portion and a constriction downstream of the upstream portion. The constriction has a smaller cross-sectional area than the upstream portion. The localized heating arrangement is located in the liquid delivery channel and generates heat to nucleate and enlarge a bubble in the liquid. The constriction is shaped to form a seal with the bubble. The localized heating arrangement additionally generates heat to move the bubble relative to the constriction to control the flow of the liquid. A pressure regulator that comprises a liquid delivery channel connected to a liquid outlet, a sensor located adjacent the liquid outlet, a controller that operates in response to the sensor and a localized heating arrangement. The liquid delivery channel includes an upstream portion, and a constriction located between the upstream portion and the liquid outlet. The constriction has a smaller cross-sectional area than the upstream portion. The localized heating arrangement is located in the liquid delivery channel and generates heat in response to the controller to nucleate and enlarge a bubble in the liquid. The constriction is shaped to form a seal with the bubble. The localized heating arrangement additionally generates heat to move the bubble relative to the constriction to control the flow of the liquid to the liquid outlet.

Bubble valve and bubble valve-based pressure regulator

A switching element that selectively couples a first optical path to a second optical path through an index-matching fluid includes a tapering region along each of the optical paths to achieve high coupling efficiency at both ends of substrate waveguides that form portions of the two optical paths. The two substrate waveguides are separated by a gap that is filled with the index-matching fluid in order to optically couple the two waveguides. The ends of the waveguides located at the gap have relatively large cross sectional areas to promote high coupling efficiency across the gap. For example, the cross sectional dimensions may be approximately 16 .mu.m.times.8 .mu.m at the interior ends of the two substrate waveguides. On the other hand, the exterior ends have significantly smaller cross sectional areas in order to promote high coupling efficiency to optical fibers. For example, the cross sectional dimensions of an external end may be 8 .mu.m.times.8 .mu.m. The substrate waveguides are adiabatically tapered in order to inhibit reflection. In another embodiment, the tapering regions of the two optical paths are formed along the optical fibers, rather than along the substrate waveguides.

Switching element having an expanding waveguide core

The method builds upon the highly repeatable properties of commercial optical fiber, and using commercial fiber for the waveguides in a fabric of optical switches. The method describes assembly of the fabric, locating the intersections, and a structure for placing the mating resistor.

Method for making fluid optical switches

A thermal optical switching cell has a channel of either gas or boilable liquid that crosses an optical waveguide at a forty-five degree angle. Two or more appropriately placed heaters use the water/steam/dry states of thermal ink jet technology to quickly insert, or extract, boilable liquid respectively into, or from, the channel. The boilable liquid has an index of refraction close to that of the guide. In the wet state, the channel contains the liquid and nearly all the light of the incoming guide traverses the liquid along the axis of the guide. In the dry state, the channel contains gas. Total internal reflection (TIR) occurs and light is directed at right angles away from the axis of the incoming channel. Adding a second waveguide, perpendicular to, and intersecting the first waveguide at the channel, forms a cross-bar switch. These liquid switching cells toggle between the wet and dry states. No power is required to hold the switch in the most recent state. A monitoring signal is described that can be used to determine the state of the switch. The dry state of these cells is totally internally reflecting. The wet state, however, is transmissive with a small, but objectionable, amount of reflection. A push-pull optical circuit is formed using paired cells and at least one TIR mirror. One of the cells of the circuit is always in the TIR, state to provide good isolation. This circuit has the property of reporting the state of the switch-pair so that a fault can be detected. If a fault is detected, repeated activation pulses can be applied to force liquid into the correct places to maintain proper operation of the circuit.

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Mountain View, CA, United States of America

David K Donald