Chinese Academy of Sciences

Ninghua Zhu

Li Wang

Wei Chen

Nuannuan Shi

Wei Li

Jianguo Liu

Tengfei Hao

Yu Liu

Jian Tang

Dapeng Liu

Wenhui Sun

Haiqing Yuan

Xin Wang

Changda Xu

Dechao Ban

Jinjin Guo

Jiasheng Wang

Jinhua Bai

A tunable external cavity laser with dual gain chips, including: a polarization beam splitter having a beam splitting surface arranged at an angle of 45° with respect to a first direction and a second direction perpendicular to the first direction; a first gain chip arranged in the first direction; a second gain chip arranged in the second direction; a feedback cavity arranged in the first direction, wherein the feedback cavity and the first gain chip are respectively arranged on two opposite sides of the polarization beam splitter, and the feedback cavity includes at least one independent Fabry-Perot etalon, at least one air gap Fabry-Perot cavity and a mirror that are arranged in the first direction. The polarization beam splitter and the two gain chips cooperate to share the feedback cavity, so that a wavelength and a phase may be adjusted, and a larger tuning range may be obtained.

Tunable external cavity laser with dual gain chips

A broadband tuning system includes a first chip and a second chip. The first chip includes a first light amplification region, a first forward grating region and a first backward grating region that are sequentially arranged in a first direction. The first light amplification region is configured to amplify a first light source and to turn on or turn off the first light source, and the first forward grating region and the first backward grating region are configured to tune the first light source. The second chip includes a second light amplification region, a second forward grating region and a second backward grating region that are sequentially arranged in a second direction. The second light amplification region is configured to amplify a second light source and to turn on or turn off the second light source, and the second forward grating region and the second backward grating region are configured to tune the second light source.

Broadband tuning system and method

A frequency spectrum detection system including: a frequency-scan light source, a phase modulator, an optical filter, an optical fiber, a photodetector, a power divider, an electric amplifier, a combiner, an electric filter, and an oscilloscope. The frequency-scan light source, the phase modulator, the optical filter, the photodetector, and the electric amplifier form a ring-shaped optoelectronic oscillator resonant cavity, which is configured to generate a frequency-scan signal. The combiner is configured to receive a signal to be measured. The phase modulator is configured to modulate the combined electrical signal onto a frequency-scan optical signal. The optical filter is configured to selectively attenuate or amplify one sideband of double sidebands of the double-sideband phase-modulated optical signal. The photodetector is configured to detect a signal filtered by the optical filter.

Frequency spectrum detection system

A Fourier domain mode-locked optoelectronic oscillator includes a laser light source, a phase modulator, an optical notch filter, a photodetector, an electrical amplifier and a power divider; wherein the laser light source, the phase modulator, the optical notch filter and the photodetector together form a swept microwave photonic filter. The passband of the swept microwave photonic filter is determined by the difference in wavelength corresponding to the laser light source and the notch positions of the optical notch filter. In the present disclosure, the laser light source, the phase modulator, the optical notch filter, and the photodetector are configured to form a fast swept microwave photonic filter, the sweeping of a passband of the microwave photonic filter is realized by the sweeping of the laser light source or the optical notch filter, and the change in the filter's passband is matched with the latency for delivering a signal in the optoelectronic oscillator loop for one trip. As such, Fourier domain mode locking is realized, and a broadband adjustable chirped microwave signal can be output.

Fourier domain mode-locked optoelectronic oscillator

An integrated Fourier domain mode-locked optoelectronic oscillator and its application and a communication system are provided, which relates to the technical field of microwave photonics. The integrated Fourier domain mode-locked optoelectronic oscillator includes an optoelectronic chip and an electronic chip. The optoelectronic chip includes a laser, a modulator, an optical notch filter, and a photodetector coupled via an optical waveguide. The electronic chip includes an electrical amplifier and a power splitter coupled via a coplanar microwave waveguide. The volume, weight and power consumption of the Fourier domain mode-locked optoelectronic oscillator is greatly reduced by integrating all the devices on the chip. A tunable sweeping microwave signal output is realized, and the sweeping speed of the output signal is increased. The integrated Fourier domain mode-locked optoelectronic oscillator can be used in radars and communication systems.

Integrated fourier domain mode-locked optoelectronic oscillator, application and communication system

Embodiments of the present disclosure disclose an optoelectronic oscillator including an optical chip and a microwave chip. The optical chip is implemented by fabricating different optoelectronic devices on an integrated optical substrate, comprising: a laser assembly; a mode selection device coupled to the laser assembly, and configured to receive the laser and perform mode selection; an optical delay module coupled to the mode selection device; and a detector coupled to the optical delay module. The microwave chip is a microwave integrated circuit formed by fabricating microwave elements on a semiconductor substrate, comprising: a microwave processing circuit configured to receive microwave signal and perform signal processing; a coupler coupled to the microwave processing circuit, and configured to provide a part of the microwave signal to a phase shifter and output the other part thereof; and a phase shifter configured to feed the phase-shifted microwave signal to the laser assembly.

Optoelectronic oscillator

A multi-band channel encrypting switch control device is provided. The device comprises a transmission part and a receiving part. The transmission part comprises: a first controller to store a secret key and to send a digital signal; an encrypting unit to encrypt the digital signal; a multi-band transmitter to select a plurality of wavebands to transmit the encrypted signal on the plurality of wavebands under control of the secret key; and a switch. The receiving part comprises: a multi-band detector to receive the encrypted signal transmitted on the plurality of wavebands; a decrypting unit to decrypt the encrypted signal; and a second controller to store the secret key and to decide whether or not to issue a switch signal by processing the signal and making decisions using the process result. A transmission device, a receiving device, and a control method are also provided. The encrypted data is transmitted via different channels to reduce possibility of signal interception during the transmission, thereby improving security significantly.

Multi-band channel encrypting switch control device and control method

The present invention discloses a semiconductor laser comprising an optical waveguide structure which may include a lower waveguide layer, an active layer of multiple quantum wells and an upper waveguide layer, which are successively stacked from bottom to top, a grating layer being formed on upper portion of the active layer, wherein the upper waveguide layer, a cladding layer and a contact layer are formed as a ridge which has a light incidence end surface and a light output end surface, wherein a beam expanding structure is formed on one end of the output end surface. The beam expanding structure has a beam expanding portion with a shape gradually contracted inwards from the light output end surface. Preferably, the beam expanding portion has a horizontal divergence angle of 5&#xb0; to 20&#xb0;.

High speed semiconductor laser with a beam expanding structure

An integral chip is disclosed by embodiments of the present disclosure, including: two mono-mode vertical coupling gratings, two modulation modules, one 2&#xd7;1 multi-mode interference coupler, and one dual-mode vertical coupling grating. The integral chip is capable of operating in dual wavelengths and dual polarization states by combination of polarization multiplexing and wavelength division multiplexing so as to realize modulation of complex formats and to enhance data modulation rate.

Integrated chip

A 3D package device of a photonic integrated chip matching circuit, comprising: a first carrier substrate; a first microwave transmission line array formed by evaporation on the top surface of the first carrier substrate to provide bias voltages and high-frequency modulation signals to the photonic integrated chip; a second carrier substrate formed perpendicularly to the first carrier substrate or to have a certain angle with respect to the first carrier substrate, so as to constitute a 3D structure; a second microwave transmission line array formed by evaporation on the bottom surface of the second carrier substrate to match electrodes of the first microwave transmission line array, the second microwave transmission line array being soldered or sintered with the electrodes of the first microwave transmission line array; an electrode array formed by evaporation on a side surface or two opposite side surfaces of the second carrier substrate; and a microwave circuit.

3D package device of photonic integrated chip matching circuit

An optical fiber secure communication apparatus and a data encryption method therefor are provided. The apparatus comprises a transmitter and a receiver being connected with each other via an optical fiber. The transmitter comprises a PPC processor unit, a field programmable gate array test board, a light-emitting module, an optical fiber coupler and a connection optical fiber. The receiver comprises a wavelength division multiplexer, a connection optical fiber, a photodetector, a field programmable gate array test board, a PPC processor unit and a signal output interface. At the transmitter end, two or more paths of input data are forwarded by the PPC, encrypted by the FPGA and then transmitted to the light-emitting module of two or more wavelengths for conversion from electrical signals into optical signals. At the receiver end, signals of two or more wavelengths enter the photodetector for conversion into electrical signals, which are decrypted by the FPGA and then forwarded by the PPC for output. With the present invention, the security of transmission data is improved and the difficulty in cracking data is increased.

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Beijing, China

Ninghua Zhu