Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A switching element defines a transmitting state and a reflecting state for a pair of intersecting waveguides that have a gap at their intersection. In the preferred embodiment, the switching element exhibits total internal reflection at the gap sidewall from one waveguide to the other when not in the transmitting state. In the transmitting state, index-matching liquid fills the gap, enabling light to continue in the original waveguide direction. The switching element may use ink jet techniques or bubble techniques to displace index-matching liquid. The index-matching fluid may be projected from a gap between the waveguides by a jet mechanism, or a vapor or dissolved gas bubble may be formed to fill the gap between the waveguides to provide the reflecting state for the switching element. Using either of the techniques, heaters are employed to initiate the switching operation. In some embodiments, more than one heater is utilized.

Abstract: A polarization insensitive fiber laser. A pair of 45 degree Faraday rotators are positioned on either end of the fiber gain source. The resulting laser is insensitive to external perturbations with respect to known entrance and exit polarization states of the laser light. Modelocking, both passive and active, is possible. Configuration wherein the fiber is a combination of polarization preserving and Erbium-doped, and a saturable absorber is included provide a self-starting, polarization insensitive modelocked laser.

Abstract: A CPM mode-locked fiber ring laser including an ion-implanted semiconductor saturable absorber providing sub-picosecond pulses at rapid repetition rates. The laser provides compact, turn-key capability and is polarization insensitive.

Abstract: Compounds of formula (I) are provided, wherein R.sup.1 represents OH or OCH.sub.3 ; R.sup.2 represents OH or H; R.sup.3 represents methyl, ethyl, propyl or allyl; X represents O, (H,OH) or (H,H); m represents 0 or 1; n represents 1 or 2; and pharmaceutically acceptable derivatives thereof; provided that when n is 1, then R.sup.3 is allyl or propyl. The compounds are indicated inter alia as immunosuppresive agents.

Abstract: Compounds of formula (I), in which [R.sup.1 and R.sup.2 ], [R.sup.3 and R.sup.4 ] and [R.sup.5 and R.sup.6 ] represent a carbon-carbon bond or two hydrogen atoms; R.sup.2 additionally represents alkyl; R.sup.7, R.sup.8 and R.sup.9 represent groups including H or OH, R.sup.10 has various significances including alkyl and alkenyl; X and Y represent groups including O and (H, OH); R.sup.14, R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.19, R.sup.22 and R.sup.23 represent H or alkyl; R.sup.20 and R.sup.21 represent groups including O, (H, OH) and (H, O-alkyl), n is 1, 2 or 3, and in addition, Y, R.sup.10 and R.sup.23, together with the carbon atoms to which they are attached, may represent a heterocyclic ring, (with certain provisos) are described. Processes for making the compounds and pharmaceutical formulations containing them, e.g. for use as immunosuppressive agents, are also described.

Abstract: A figure-8 loop laser having a controllable phase shifter in a Sagnac loop (non-linear amplifying loop mirror). A half-wave plate in series with Faraday optical rotators provide a switchable non-reciprocal 180-degree phase shifter that allows the birefringence of the fiber loop to be adjusted during continuous wave operation. The phase shifter is activated during continuous wave operation to find a minimum threshold and then is turned off, placing the laser in optimum state for mode locking.

Abstract: There are provided compounds of formula (I), wherein R.sup.1 represents H, OH or alkoxy; R.sup.2 represents H; in addition R.sup.1 and R.sup.2 may together represent a second bond between the carbon atoms to which they are attached; R.sup.3 represents methyl, ethyl, propyl or allyl; R.sup.4 represents H, OH, alkyl, alkoxy, halogen, amino, S-alkyl, NHCHO or NHCO-alkyl; n represents 1 or 2; X represents O, (H, OH), (H, H) or .dbd.NH; and Y represents an optionally substituted cyclohexyl or substituted cyclopentyl group; with various provisos. The compounds are useful, inter alia, as immunosuppressive agents.

Abstract: Compounds of formula I, ##STR1## wherein R.sup.1 represents H, OH, protected OH or alkoxy; R.sup.2 represents H; R.sup.3 represents O or (H,OH); R.sup.4 represents methyl, ethyl, propyl or allyl; R.sup.5 represents OH, protected OH or alkoxy; R.sup.6 represents OH; R.sup.7 represents OH, alkoxy or NR.sup.8 R.sup.9 where R.sup.8 and R.sup.9 independently represent H, alkyl or aryl; in addition, R.sup.1 and R.sup.2 may together represent a second bond between the carbon atoms to which they are attached; and R.sup.6 and R.sup.7 may together represent O; and pharmaceutically acceptable salts thereof; are useful inter alia as immunosuppressive agents. The invention also provides the novel compounds of formula I.

Abstract: There are described compounds of formula I, ##STR1## wherein R.sup.1 represents H or OH; R.sup.2 represents H; in addition, R.sup.1 and R.sup.2 may together represent a second carbon-carbon bond between the carbon atoms to which they are attached; R.sup.3 represents OH or OCH.sub.3 ; X represents O or (H,OH); and Y represents O or N--OR.sup.4, in which R.sup.4 represents H or alkyl C.sub.1-6 ; provided that when R.sup.1 is OH, R.sup.2 is H and X is O, then Y does not represent O.Processes for their production and compositions containing them, eg. for use as immunosuppressive agents, are also described.

Abstract: Thid disclosure relates to a novel class of hydroxamic acid based collagenase inhibitor derivatives. The disclosure further relates to pharmaceutical compositions containing such compounds and to the use of such compounds and compositions in the treatment of collagenase induced diseases.

Abstract: This invention relates to compounds of the formula ##STR1## wherein R.sub.1 represents lower alkyl, phenyl, or phenyl lower alkyl; R.sub.2 represents lower alkyl; and R.sub.5 represents lower alkyl. These compounds are useful as intermediates in the preparation of collagenase inhibiting compounds which are useful in the treatment of arthritis and are of the formula ##STR2## wherein R.sub.1 represents lower alkyl, phenyl or phenyl lower alkyl; R.sub.2 and R.sub.4 represent lower alkyl; and R.sub.3 represents lower alkyl, benzyloxyalkyl, alkoxybenzyl or benzyloxybenzyl wherein the oxyalkyl or alkoxy moiety contain 1 to 6 carbon atoms; and a, b, and c represent chiral centers with optional R or S stereochemistry.

Abstract: This disclosure relates to a novel class of hydroxamic acid based collagenase inhibitor derivatives. The disclosure further relates to pharmaceutical compositions containing such compounds and to the use of such compounds and compositions in the treatment of collagenase induced diseases.

Abstract: This invention relates to compounds of the formula: ##STR1## wherein R.sub.1 represents lower alkyl, phenyl or phenyl lower alkyl;R.sub.2 and R.sub.4 represent lower alkyl; andR.sub.3 represents lower alkyl, benzyloxyalkyl, alkoxybenzyl or benzyloxybenzyl wherein the oxyalkyl or alkoxy moiety contain 1 to 6 carbon atoms; and a, b, and c represent chiral centers with optional R or S stereochemistry. These compounds inhibit collagenase and are useful in the treatment of arthritis. Also disclosed are processes for manufacture of the compounds and pharmaceutical compositions containing them.

Abstract: A thermal ink jet printer is disclosed in which ink droplets are ejected from an orifice by the explosive formation of a vapor bubble within the ink supply due to the application of a two part electrical pulse to a resistor within the ink supply. The electrical pulse comprises a precurser pulse and a nucleation pulse; the precurser pulse preheats the ink in the vicinity of the resistor to a temperature below the boiling temperature of the ink so as to preheat the ink while avoiding vapor bubble nucleation within the ink supply and the subsequently occuring nucleation pulse very quickly heats the resistor to near the superheat limit of the ink.

Abstract: A drop-on demand ink jet printer and a method of ink jet printing are disclosed which produce drops whose diameter have a ratio to the internal diameter of their print nozzles of 1:2 instead of the standard ratio of 2:1. This change in the basic ratio of drop diameter to print nozzle diameter is a result of the motion imparted to the print liquid by the actuation of the print nozzle. The print nozzle is cocked, released, and abruptly stopped to impart forward momentum to the print liquid near the orifice of the print nozzle. This momentum urges the liquid to be expelled from the print nozzle. Cutting the orifice of the print nozzle at an oblique angle to the run of the print nozzle creates a leading edge on the print nozzle which increases control of drop placement. The leading edge encourages formation of a single umbilicus of expelled print liquid from which a drop will be severed.