The present invention relates to a transmitter for transmitting data and for emitting electromagnetic radiation in the visible spectral range, wherein the transmitter comprises a) a radiation source for generating and emitting first electromagnetic radiation, b) a modulator being adapted to modulate the first electromagnetic radiation depending on the data to be transmitted generating modulated first electromagnetic radiation, and c) a frequency converter for converting at least a part of the modulated first electromagnetic radiation into modulated second electromagnetic radiation, said modulated second electromagnetic radiation being different from the modulated first electromagnetic radiation, wherein the frequency converter comprises a polymeric matrix material comprising at least one organic fluorescent colorant. Furthermore, the invention relates to an illumination device comprising such transmitter. Moreover, the invention relates to a data transmission system comprising such a transmitter as well as a receiver and a data analyzer.

An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

An optical transmission apparatus of an embodiment is an apparatus for redundantly transmitting a multiplexed signal obtained by multiplexing N (N is an integer of 2 or greater) optical signals having different wavelengths, the apparatus including: a first demultiplexing unit to which a first multiplexed signal is input, the first demultiplexing unit configured to demultiplex the input first multiplexed signal into the N optical signals; N first detection units to which the N optical signals demultiplexed by the first demultiplexing unit are respectively input, each of the N first detection units configured to detect presence or absence of deterioration of a corresponding input optical signals of the input optical signals based on a signal level of the corresponding input optical signal; a second demultiplexing unit to which a second multiplexed signal is input, the second demultiplexing unit configured to demultiplex the input second multiplexed signal into the N optical signals; N second detection units to which the N optical signals demultiplexed by the second demultiplexing unit are respectively input, each of the N second detection units configured to detect presence or absence of deterioration of a corresponding input optical signal of the input optical signals based on a signal level of the corresponding input optical signal; and a selection unit configured to select, based on the detection result of presence or absence of deterioration of each of the optical signals by the first detection units and the second detection units, N optical signals having different wavelengths from either the optical signals demultiplexed by the first demultiplexing unit or the optical signals demultiplexed by the second demultiplexing unit.

An optical transmission system includes: a first optical transmitting unit for transmitting a first optical signal having a first wavelength; a second optical transmitting unit for transmitting a second optical signal having a second wavelength; an output adjustment unit for acquiring the first optical signal and the second optical signal, adjusting signal intensities of the acquired optical signals, and outputting the optical signals; a multiplexer for multiplexing the first optical signal and the second optical signal that have been subjected to signal intensity adjustment and outputting a multiplexed signal; an amplifier for amplifying the multiplexed signal; a first optical receiving unit for receiving the amplified first optical signal; and a second optical receiving unit for receiving the amplified second optical signal. The output adjustment unit adjusts the signal intensities of the first optical signal and the second optical signal such that the signal intensity of the first optical signal received by the first optical receiving unit is larger than or equal to a first predetermined value, and the signal intensity of the second optical signal received by the second optical receiving unit is larger than or equal to a second predetermined value.

An optical transmission system includes: a first optical transmitting unit for transmitting a first optical signal having a first wavelength; a second optical transmitting unit for transmitting a second optical signal having a second wavelength; an output adjustment unit for acquiring the first optical signal and the second optical signal, adjusting signal intensities of the acquired optical signals, and outputting the optical signals; a multiplexer for multiplexing the first optical signal and the second optical signal that have been subjected to signal intensity adjustment and outputting a multiplexed signal; an amplifier for amplifying the multiplexed signal; a first optical receiving unit for receiving the amplified first optical signal; and a second optical receiving unit for receiving the amplified second optical signal. The output adjustment unit adjusts the signal intensities of the first optical signal and the second optical signal such that the signal intensity of the first optical signal received by the first optical receiving unit is larger than or equal to a first predetermined value, and the signal intensity of the second optical signal received by the second optical receiving unit is larger than or equal to a second predetermined value.

Configurations for a modal interference device used for wavelength locking are disclosed. The modal interference device may be an interference device that includes an input waveguide, an interference waveguide, and an output waveguide. A fundamental mode of light may be launched into the input waveguide and the interference waveguide may receive the fundamental mode and generate a higher order mode of light, where the two modes of light may be superimposed while propagating through the interference waveguide. The two modes of light may be received at an output waveguide that collapses the two modes into a single mode and generates an output signal corresponding to the interference between the two modes of light. The output signal may be used to wavelength lock a measured wavelength to a target wavelength. The multiple output waveguides may produce output signals that have dead zones that do not align with one another for any wavelength in the wavelength range of interest.

Configurations for a modal interference device used for wavelength locking are disclosed. The modal interference device may be an interference device that includes an input waveguide, an interference waveguide, and an output waveguide. A fundamental mode of light may be launched into the input waveguide and the interference waveguide may receive the fundamental mode and generate a higher order mode of light, where the two modes of light may be superimposed while propagating through the interference waveguide. The two modes of light may be received at an output waveguide that collapses the two modes into a single mode and generates an output signal corresponding to the interference between the two modes of light. The output signal may be used to wavelength lock a measured wavelength to a target wavelength. The multiple output waveguides may produce output signals that have dead zones that do not align with one another for any wavelength in the wavelength range of interest.

The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate respective subcarrier frequencies which represent subchannels of an ITU channel to which client signals can be mapped. In one embodiment, subchannels are polarization interleaved to reduce crosstalk. In another embodiment, polarization multiplexing is used to increase the spectral density. Client circuits can be divided and combined with one another before being mapped, independent of one another, to individual subchannels within and across ITU channels. A crosspoint switch can be used to control the client to subchannel mapping, thereby enabling subchannel protection switching and hitless wavelength switching. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of the client circuits mapped to these subchannels across the nodes of a WDM network.

The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate respective subcarrier frequencies which represent subchannels of an ITU channel to which client signals can be mapped. In one embodiment, subchannels are polarization interleaved to reduce crosstalk. In another embodiment, polarization multiplexing is used to increase the spectral density. Client circuits can be divided and combined with one another before being mapped, independent of one another, to individual subchannels within and across ITU channels. A crosspoint switch can be used to control the client to subchannel mapping, thereby enabling subchannel protection switching and hitless wavelength switching. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of the client circuits mapped to these subchannels across the nodes of a WDM network.

An optical signal transceiver in a transistor outline package includes a component base, a laser device, a first wavelength division multiplexing prism and a second wavelength division multiplexing prism, a first photodetector, and a second photodetector. The component base is inside the transistor outline package and supports the laser device, the laser device emitting light to the outside of the transistor outline package. The first and second prisms and the first photodetector and the second photodetector are also located on the component base. Light output as optical signals sequentially pass through the first and second multiplexing prisms. The first input optical signal is transmitted to the first photodetector through the first prism, and the second input optical signal passes through the first prism and is passed on to the second photodetector via the second prism.