A generator device for generating an arbitrary optical pulse pattern includes: a light source to provide primary laser pulses, a distributor to provide a plurality of primary optical pulses by distributing light of the primary laser pulses (LB00.sub.k) into a plurality of branches, a combiner to form an output signal by combining modulated optical signals from the branches, and a controller unit to provide control signals for controlling optical modulators of the branches, wherein a first branch comprises a first optical modulator to form a first modulated optical signal from primary optical pulses of the first branch, wherein a second branch comprises a second optical modulator to form a second modulated optical signal from primary optical pulses of the second branch, and wherein a propagation delay of the second branch is different from a propagation delay of the first branch.

A pluggable optical module according to the present invention includes a pluggable electric connector configured so as to be insertable into and removable from an optical transmission apparatus, and capable of transmitting/receiving a data signal to/from the optical transmission apparatus, a drive unit configured to output first/second driving signals by amplifying the data signal, an optical signal output unit configured to output a first/second optical signal modulated according to the first/second drive signal, a light-intensity monitoring unit configured to monitor intensities of the first/second optical signals, a control unit configured to control a gain of the drive unit so as to adjust a difference between the intensities of the first/second optical signals based on a result of the monitoring by the light-intensity monitoring unit, and a pluggable optical receptor configured so that an optical fiber can be inserted thereinto and removed therefrom, and configured to output the first/second optical signals.

An ophthalmic imaging apparatus that captures a tomographic image of an subject's eye based on light obtained by combining a return light with a reference light, the return light being from the subject's eye when irradiated with a measurement light, the reference light corresponding to the measurement light includes a first optical fiber disposed in an optical path of the reference light and including a light guide portion for guiding the reference light, and a second optical fiber disposed in an optical path of the measurement light and including a light guide portion for guiding the measurement light, wherein a diameter of each of the light guide portions of ejection ends of the first optical fiber and the second optical fiber is larger than a diameter of a light guide portion in a position different from a position of each of the ejection ends.

An initial change and a secular change in an optical characteristic and a high frequency characteristic in a case where an optical modulator is mounted in a package of an optical transmission apparatus are suppressed while improving a space utilization rate in the package of the optical transmission apparatus. An optical modulator that is electrically connected to an electric circuit configured on a circuit board, includes: a package that houses an optical modulation element; and a signal input part or the like for inputting an electric signal for causing the optical modulation element to perform an modulation operation from the electric circuit, in which the package has, on a part of a bottom surface facing the circuit board, a first protrusion portion protruding from the bottom surface, and the signal input part is provided on an upper surface of the first protrusion portion.

An optical modulation element that can be housed in the same housing together with an electronic circuit is implemented without deteriorating the high-frequency characteristics and the optical modulation characteristics and without increasing a size of the housing. An optical modulation element includes two Mach-Zehnder type optical waveguides that are provided on a substrate, a branched waveguide that branches input light which is input from an outside of the substrate into two light beams, two connection waveguides that respectively guide the light beams branched by the branched waveguide to the two Mach-Zehnder type optical waveguides, and electrodes that respectively control optical waves propagating in optical waveguides configuring the two Mach-Zehnder type optical waveguides, in which respective parallel waveguides of the two Mach-Zehnder type optical waveguides are configured to extend along one side of the substrate, the branched waveguide is disposed such that light is input from a direction of the one side, and the branched waveguide is formed to be line-symmetrical with respect to a propagation direction of the light input to the branched waveguide and to output the two branched light beams in a direction different from the propagation direction.

An optical waveguide apparatus including a first dispersion unit and a separation unit. The first dispersion unit is connected to the separation unit, the first dispersion unit is configured to disperse a frequency component of at least one first optical signal, and the separation unit is configured to separate, into at least one second optical signal based on configuration information, the frequency component that is of the at least one first optical signal and that is dispersed by the first dispersion unit. The separation unit is implemented by a variable optical waveguide, and the variable optical waveguide is an optical waveguide that implements at least one of the following functions based on the configuration information: forming an optical waveguide, eliminating an optical waveguide, and changing a shape of an optical waveguide.

An optical modulator includes first and second waveguides; a first phase shifter provided in at least one of the first and second waveguides and configured to control a phase of the laser beam; a first optical element configured to combine the laser beam propagating through the first waveguide and the laser beam propagating through the second waveguide and separate the combined laser beam into two laser beams; a third (fourth) waveguide on which one (the other) of the laser beams separated by the first optical element is incident; a second phase shifter provided in at least one of the third and fourth waveguides and configured to control a phase of the laser beam; and a second optical element configured to combine the laser beam propagating through the third waveguide and the laser beam propagating through the fourth waveguide and emit the laser beam in the superposition state.

An optical waveguide element is provided to effectively reduce an optical absorption loss of waveguide light which may occur at an intersecting part between an optical waveguide and an electrode without causing deterioration in optical characteristics and degradation of long-term reliability of the optical waveguide element. The optical waveguide element includes an optical waveguide formed in a substrate, and an electrode controlling optical waves propagated in the optical waveguide and having an intersecting part intersecting the optical waveguide thereabove. A portion of a resin layer is provided between the optical waveguide and the electrode in a portion of the substrate including the intersecting part. A corner of the resin layer on a side of the electrode is constituted to be a curve in a cross section in an extending direction of the electrode.

A narrow linewidth laser includes a passive ring resonant cavity, an FP resonant cavity, and a first gain region. The passive ring resonant cavity and the FP resonant cavity are combined to form an M-Z (Mach-Zehnder interference structure) compound external cavity structure, and the M-Z compound external cavity structure is at least used for providing wavelength selection and narrowing laser linewidth. The first gain region is provided on the outer side of the M-Z compound external cavity structure and is used for providing a gain for the whole laser. The narrow linewidth laser is simple in structure, high in side-mode suppression ratio, narrow in linewidth, and high in output power. By further integrating a PN junction region or MOS junction region, broadband and rapid tuning with low power consumption can also be achieved, and tuning management is simple.

Methods and systems are described for modulating optical signals. An example method may comprise supplying, via a waveguide, an optical signal to a resonator optically coupled to the waveguide. The method may comprise modulating a phase of the optical signal based on at least one layer comprising an electro-optic material having an electro-refractive property and an electro-absorptive property. The modulating of the phase may be based on using the at least one layer to tune a coupling of the waveguide and the resonator between being under-coupled and being over-coupled. The method may comprise outputting, via the waveguide, the modulated optical signal.