Abstract: Disclosed herein are a class of compounds useful in cell culture, in particular, the in vitro culture of stem cells. The compounds have been found to promote the survival and/or maintenance of stem cells in (or during) culture and/or throughout passage.

Abstract: One or more input access waveguides are connected to an optical splitter arranged to divide the light into two or more output waveguides, at least two of the splitter's output access waveguides are used to form a Mach-Zehnder interferometer modulator where at least one arm of the interferometer has a phase modulator electrode and a single electrical contact is arranged to apply a common voltage simultaneously to a selected portion in each arm, or selected portions in each arm of the waveguides that are disposed after the splitter but preceding the phase modulation electrodes, or alternatively the single electrical contact is arranged to apply the voltage to a selected portion of the input access waveguide connected to the splitter and in one or more selected portions of one or both of the arms after the splitter but preceding the phase modulation electrodes to provide gain or reduced optical loss.

Abstract: An optical waveguide splitter with a symmetric splitting power ratio having one input port and two output ports, includes a substrate and one or more vertical waveguide layers deposited thereon or diffused thereinto, and optionally one or more cladding layers deposited upon the waveguide layer(s). The waveguide layers and optionally one or more cladding layer together and optionally with the substrate form a profile of the refractive index that supports the propagation of light in a plane substantially parallel to the substrate. On both sides of the input port, the waveguide sidewalls terminate at a depth deeper than the location of the peak intensity of the beam transporting propagating light energy within the input port, and the sidewalls on both sides of each output port terminate at a depth shallower than the location of the peak intensity of the beam transporting the majority light energy within each output port.

Abstract: One or more input access waveguides are connected to an optical splitter arranged to divide the light into two or more output waveguides, at least two of the splitter's output access waveguides are used to form a Mach-Zehnder interferometer modulator where at least one arm of the interferometer has a phase modulator electrode and a single electrical contact is arranged to apply a common voltage simultaneously to a selected portion in each arm, or selected portions in each arm of the waveguides that are disposed after the splitter but preceding the phase modulation electrodes, or alternatively the single electrical contact is arranged to apply the voltage to a selected portion of the input access waveguide connected to the splitter and in one or more selected portions of one or both of the arms after the splitter but preceding the phase modulation electrodes to provide gain or reduced optical loss.

Abstract: Method for modifying the splitting or combining ratio of a first multimode interference (MMI) coupler (100), which first coupler is arranged to convey light from one or several input waveguides to one or several output waveguides, wherein a film (103a) of a material is arranged over the first coupler, wherein the film is strained so that a force is applied by the film to the surface of the first coupler, and so that the refractive index profile in the material of the first coupler changes as a consequence of the force, and wherein the splitting or combining ratio is modified as a consequence of the changed refractive index profile.

Abstract: Method for modifying the splitting or combining ratio of a first multimode interference (MMI) coupler (100), which first coupler is arranged to convey light from one or several input waveguides to one or several output waveguides, wherein a film (103a) of a material is arranged over the first coupler, wherein the film is strained so that a force is applied by the film to the surface of the first coupler, and so that the refractive index profile in the material of the first coupler changes as a consequence of the force, and wherein the splitting or combining ratio is modified as a consequence of the changed refractive index profile.

Abstract: An optical waveguide splitter with a symmetric splitting power ratio having one input port and two output ports, includes a substrate and one or more vertical waveguide layers deposited thereon or diffused thereinto, and optionally one or more cladding layers deposited upon the waveguide layer(s). The waveguide layers and optionally one or more cladding layer together and optionally with the substrate form a profile of the refractive index that supports the propagation of light in a plane substantially parallel to the substrate. On both sides of the input port, the waveguide sidewalls terminate at a depth deeper than the location of the peak intensity of the beam transporting propagating light energy within the input port, and the sidewalls on both sides of each output port terminate at a depth shallower than the location of the peak intensity of the beam transporting the majority light energy within each output port.

Abstract: An optical light splitter includes or is connected to at least two input waveguides (4; 6, 7; 18, 19; 32,33) for light. The light splitter (1, 2, 30, 40), on the side opposite to the input waveguide or input waveguides (4; 6, 7; 18, 19; 32, 33; 41, 42) transitions into at most one output waveguide (8, 10, 20, 34) in the direction of propagation of the incoming light. A surface (14, 25, 31, 45) is present set at an angle to the direction of propagation of the light in that part of the light splitter that is opposite to the input waveguide or input waveguides, the surface is present where the light splitter has an image from incoming light, and internal corners are not present in the part.

Abstract: A Mach Zehnder (MZ) modulator (1) includes a splitter (4) for splitting incident light in one wave guide (3) into two modulator arms (5,6) of the MZ and a combiner (7) that combines light from the two arms (5,6) into an output mode, where electrodes (9,10) are present in connection with the arms (5,6) for changing the refractive index in the arms in order to modulate incident light so that the light is amplified or so that an extinction, due to interference between the light in the two arms, takes place. The splitter (4) is arranged to split incident light equally into the two arms (5,6) and a part (11) of one of the arms (5) between the electrode (9) and the combiner (7) is designed to cause an intentional loss of light in the wave guide (5), whereby a desired asymmetry in transmission of the two arms (5,6) occurs.

Abstract: An optical light splitter includes or is connected to at least two input waveguides (4; 6, 7; 18, 19; 32,33) for light. The light splitter (1, 2, 30, 40), on the side opposite to the input waveguide or input waveguides (4; 6, 7; 18, 19; 32, 33; 41, 42) transitions into at most one output waveguide (8, 10, 20, 34) in the direction of propagation of the incoming light. A surface (14, 25, 31, 45) is present set at an angle to the direction of propagation of the light in that part of the light splitter that is opposite to the input waveguide or input waveguides, the surface is present where the light splitter has an image from incoming light, and internal corners are not present in the part.

Abstract: A transition part (1) between two optical waveguides (2,3) with different index contrast is characterised in that the transition part (1) includes a non-adiabatically up-tapered longitudinal section (8), and in that the transition (7) between the two waveguides (2,3) is arranged after the up-tapered longitudinal section (8) as seen along the main direction (L) of propagation of the light. A method of manufacturing the transition part is also described.

Abstract: A Mach Zehnder (MZ) modulator (1) includes a splitter (4) for splitting incident light in one wave guide (3) into two modulator arms (5,6) of the MZ and a combiner (7) that combines light from the two arms (5,6) into an output mode, where electrodes (9,10) are present in connection with the arms (5,6) for changing the refractive index in the arms in order to modulate incident light so that the light is amplified or so that an extinction, due to interference between the light in the two arms, takes place. The splitter (4) is arranged to split incident light equally into the two arms (5,6) and a part (11) of one of the arms (5) between the electrode (9) and the combiner (7) is designed to cause an intentional loss of light in the wave guide (5), whereby a desired asymmetry in transmission of the two arms (5,6) occurs.

Abstract: A transition part (1) between two optical waveguides (2,3) with different index contrast is characterised in that the transition part (1) includes a non-adiabatically up-tapered longitudinal section (8), and in that the transition (7) between the two waveguides (2,3) is arranged after the up-tapered longitudinal section (8) as seen along the main direction (L) of propagation of the light. A method of manufacturing the transition part is also described.