52results about How to "Improve OSNR" patented technology

An ink jet printer comprising an ink jet print head having at least one row of a plurality of ink ejecting ports for ejecting ink droplets along a plurality of ink droplet paths, the ink jet print head residing at a first elevation; a collimated light source and a detector each residing at a second elevation that is lower than the first elevation, the detector positioned opposite the collimated light source, the ink jet print head being movable to a test position where the at least one row of a plurality of ink ejecting ports can fire non-printing droplets, the collimated light source directing light at the detector along a light path that intersects the plurality of ink droplet paths when the print head resides in the test position; and an aperture located in between the collimated light source and detector and proximate to the detector to limit a field of view of the detector and increase an optical signal-to-noise ratio of the detector.

An optical packet switching system in which transmission quality, reliability, and system management in optical packet switching control are improved. An optical packet switch section includes semiconductor optical amplifiers as gate switches multistage-connected on paths along which optical packets sent from a plurality of input line cards are transmitted and performs optical packet switching by broadcasting the optical packets to a plurality of gate switches, by selecting the optical packets by ON/OFF gating operation of the gate switches, and by absorbing noise signals which flow along non-selected paths by putting gate switches at a final stage into the OFF state. A switch control section exercises ON/OFF drive control over the gate switches in the optical packet switch section on the basis of port connection requests from the plurality of input line cards so as to generate requested paths.

A method protecting wavelength channel used in denseness wavelength division multiplex system of multiway multiplex system and its device, the feature is: in the dense wavelength division multiplex system, the multiplexer (MUX) adds and connects appending multiplexer, the outputting light signal of the multiplex ( MUX ) and the output of backup optics turnable unit (OTU) combine to output through the appending multiplexer, the appending multiplexer and relevant demultiplexer (DEMUX) take optics turnable unit (OTU) as backup protecting unit for system wavelength channel, the above statement demultiplexer ( DEMUX ) can add and connect appending demultiplexer to receive the signal from appending multiplexer, the appending multiplexer and appending demultiplexer take the optics turnable unit (OTU) as backup protecting unit for system wavelength channel. This invention has high utilization for wavelength resources.

The invention discloses a single mode optical fiber with ultralow loss and a large effective area and a manufacturing method thereof. A bare optical fiber of the single mode optical fiber comprises acore layer and a cladding layer from inside to outside in sequence, the core layer comprises an inner core layer and an outer core layer which are arranged from inside to outside in sequence, the radius R1 of the inner core layer is 1.5-3 microns, the relative refractive index difference delta 1 of the inner core layer is greater than or equal to 0.01% and less than or equal to 0, the radius R2 ofthe outer core layer is 5-6 microns, and the relative refractive index difference delta 2 of the outer core layer is greater than or equal to 0 and less than or equal to 0.05%. The core layer is hardly doped with germanium and is a silicon glass layer doped with fluorine and an alkali metal oxide; the cladding layer includes a depressed cladding layer and an outer cladding layer which are arranged from inside to outside in sequence, the radius R3 of the depressed cladding layer is 40-50 microns, the relative refractive index difference delta 3 of the depressed cladding layer is greater than or equal to -0.25% and less than or equal to -0.15%, the ratio R3/R2 of the radius R3 of the depressed cladding layer to the radius R2 of the outer core layer is greater than or equal to 8, the radiusR4 of the outer cladding layer is 62.5 microns, and the outer cladding layer is a pure silica glass layer. According to the single mode optical fiber with ultralow loss and the large effective area and the manufacturing method thereof, attenuation coefficients can be reduced, and the effective area is increased.

A transceiver having an improved transmitter optical signal to noise ratio, and methods of making and using the same.

The invention discloses a data center optical communication dispersion estimation and management method based on deep learning. The equalizer based on artificial neural network is divided into two phases. In the first phase, the artificial neural network is trained with the impulse response data of optical channel, and the model parameters of artificial neural network are optimized, and the nonlinear response model of artificial neural network is established. In the second stage, the trained artificial neural network equalizer is used to process the transmission data of the optical channel, soas to realize the estimation and compensation of the dispersion of the optical channel. The simulation results show that the equalizer based on artificial neural network improves the optical signal-to-noise ratio of optical communication and prolongs the transmission distance of optical communication.

An undersea WDM optical transmission system is provided. The system includes first and second land-based cable stations, at least one of the cable stations includes power feed equipment (PFE) supplying electrical power to the cable at a voltage of no more than about 6 kv or less. The PFE is located in at least one of the cable stations. The system also includes an undersea WDM optical transmission cable having a length corresponding to those required in the undersea regional market. The cable includes at least one optical fiber pair for supporting bidirectional communication between the first and second cable stations. At least one repeater is located along the optical transmission cable. The repeater includes at least two optical amplifiers each providing optical gain to one of the optical fibers in the optical fiber pairs. The optical gain is in a range from about 12 to 20 dB.

The add path of a dense wavelength division multiplexing (DWDM) add/drop node comprises an n:1 coupler for combining n signal sources. The combined signal is amplified and then demultiplexed. Each output of the demultiplexer is passed through a variable optical attenuator (VOA) and the VOA outputs multiplexed to form the add signal. Channels carrying no add signal and not used to control the added signals are attenuated to zero to remove a broadband noise contribution from those channels. The signal sources are run at maximum power and the signals of those channels are attenuated by the respective VOAs to control their amplitude and optimize the optical signal to noise ratio of the add signal.

The present invention relates to an optical communications system that allows improving OSNR while suppressing the power increase of pumping light for distributed Raman amplification. In the optical communications system, an optical fiber is laid in a transmission section between a transmitter station (or repeater station) and a receiver station (or repeater station), and optical signals are transmitted from the transmitter station to the receiver station via the optical fiber. In the optical communications system, pumping light for Raman amplification, outputted by a pumping light source provided in the receiver station, is fed into the optical fiber via an optical coupler, and the optical signals are distributed-Raman-amplified in the optical fiber. The transmission loss and the effective area of the optical fiber satisfy, at the wavelength of 1550 nm, a predetermined relationship.

The invention discloses an optical fiber acoustic sensing system based on broadband weak reflecting mirrors and random laser, and is applied to the field of photoelectric transmission. A broadband weak reflecting mirror array is written in a sensing optical fiber so that the random laser generated by pump light through coherent feedback can be realized and the power of the pump light can be increased. The random laser provides distributed Raman amplification for the signal light of a detection light source. The distributed Raman amplification can be used for compensating the insertion loss of the broadband weak reflecting mirror array, amplifying the feedback light and enhancing the optical signal-to-noise ratio so as to enhance the detection fallibility and acquire high spatial resolution by controlling the space between the adjacent broadband weak reflecting mirrors. Random laser amplification has lower relative intensity noise so as to acquire the low-noise distributed amplification.

The present invention relates to an optical amplifier and, in particular, it relates to multistage optical amplification having a feature for compensating for the tilt that is generated when a signal having a plurality of optical wavelengths and the like according to a wavelength division multiplexing (WDM) method is amplified in a wide bandwidth. The multistage optical amplifier comprises: a plurality of optical amplifiers that are connected in a multistage manner; and a common control section for commonly controlling pumping light powers of said plurality of optical amplifiers, wherein said common control section includes: tilt detection means for detecting amounts of tilt of each of said plurality of optical amplifiers; and tilt cancellation means for controlling the pumping light powers of said plurality of optical amplifiers so that the amounts of tilt of each of the optical amplifiers detected by said tilt detection means cancel each other.

Technology for detecting an optical data signal carried in a combined optical signal that comprises a carrier optical signal modulated by the optical data signal and also comprises ASE noise. The proposed optical data detector/receiver is provided with an SHG device adapted to generate a second harmonic optical signal of the carrier optical signal modulated by the data signal. In the signal, generated by the SHG, the ASE noise will be essentially reduced.

The invention discloses an optical fiber hydrophone remote all-optical transmission system and a design method thereof. The optical fiber hydrophone remote all-optical transmission system comprises an optical fiber output assembly, an optical fiber hydrophone multiplexing array, a remote pump gain unit, a remote pump unit and a signal receiving demodulation assembly. The optical fiber output assembly is connected with the optical fiber hydrophone multiplexing array through an optical fiber L1, the remote pump unit is connected with the remote pump gain unit through an optical fiber L2, the optical fiber hydrophone multiplexing array is connected with the remote pump gain unit through an optical fiber L3, and the remote pump gain unit is connected with the signal receiving and demodulating assembly through an optical fiber L4. The optical fiber L1 and the optical fiber L2 are both G.654E single-mode optical fibers, and the optical fiber L3 and the optical fiber L4 are both UUL-G.652 single-mode optical fibers. The optical fiber hydrophone is applied to the field of optical fiber hydrophones, the nonlinear effect of downlink optical transmission can be reduced, the injection optical power is increased, the loss of uplink and downlink transmission links is reduced, the remote amplification gain and optical power redundancy are improved, and the phase noise of a remote transmission system is reduced.

The invention belongs to the technical field of optical fiber communication. The invention provides an optical fiber preform and a preparation method thereof. The preparation method comprises the following steps: introducing hydrogen, oxygen, silicon tetrachloride and germanium tetrachloride into a blast burner, burning to generate a first deposit to form a first deposition layer, replacing germanium tetrachloride with silicon tetrafluoride, burning to generate a second deposit to form a second deposition layer, sintering an obtained hollow powder core rod, and stretching to obtain an extendedhollow core rod, and heating to enable alkali metal halide to be deposited on the inner surface of the extended hollow core rod and diffused into the extended hollow core rod to obtain an alkali metal halide doped hollow core rod, depositing silicon dioxide on the alkali metal halide doped hollow core rod by adopting an OVD process, and sintering to obtain the optical fiber preform. The preparation method of the optical fiber preform is simple and convenient to produce and easy to industrialize, the optical fiber drawn by the optical fiber preform is low in loss under a small bending radius,the connection loss is effectively reduced, the stable operation of a communication system is ensured, OSNR in optical fiber communication is effectively improved, and the transmission quality is further improved.

Provided is an optical fiber having W-shaped refractive-index distribution and in which a micro-bend loss in an actual usage waveband is reduced. The optical fiber includes a core, inner cladding that surrounds the core and has a refractive index smaller than a refractive index of the core, and outer cladding that surrounds the inner cladding and has a refractive index smaller than the refractive index of the core and larger than the refractive index of the inner cladding. When a coupling coefficient between a fundamental mode and a cladding mode is denoted by C_01-CL, a coupling coefficient between the fundamental mode and a higher-order mode is denoted by C_01-11, and a coupling coefficient between the higher-order mode and the cladding mode is denoted by C_11-CL, C_total defined as C_total=C_01-CL+C_01-11C_11-CL has a minimum value at a wavelength ranging between 1520 nm and 1630 nm.

The invention relates to a dual wavelength distribution feedback optical fiber laser based on symmetry type Bragg grating, which comprises a pumping source, an isolator, a grating and a beam splitter. The specific structure of the grating is that, uniform grating parts with a width of L1 are distributed alternately with parts without grating, which has two widthes, L2 and L3; the uniform grating parts and the parts without grating are arranged according to the ...L1L2L1L3...L3L1L3...L3L1L2L1... mode, this kind of arrangement mode is symmetry about the central, wherein, L2 = m lambada, L3=(n+0.5)lambada, lambada is the Praha period, and m,n respectively represents integer. The invention has solved the technical problems such as a poor quality of the background technic light beam, a low optical Signal-to-Noise, complex apparatus, costly, narrow output wavelength interval and non-tunable; and the invention has advantage of dual wavelength output,tunable output wavelength, very high optical Signal-to-Noise, capable of efficiently avoid ing mode competition, and a single polarization state.