Guoxiang Ning

Generalized frequency dependence of output Stokes parameters in an optical fiber system with PMD and PDL/PDG

Dependence of output optical power, Stokes vector and degree of polarization on optical frequency is presented for an optical fiber system with both polarization mode dispersion and polarization-dependent loss or gain. The newly formulated equations are generalized for input light with arbitrary degree of polarization. The spectral resolved measurements of polarization mode dispersion using partially polarized light agree well with our theory.

Tunable microwave filter that uses a high-birefringent fiber and a differential-group-delay element

We propose and experimentally demonstrate a novel and simple photonic microwave notch filter that uses a high-birefringent fiber that gives a fixed differential group delay (DGD), together with a DGD element that gives a tunable DGD. This configuration overcomes the problems of optical coherence interference and chromatic dispersion, which may occur in schemes that use fiber delay lines or fiber gratings. Also presented is a theoretical analysis for the performance of the microwave filter that uses the present configuration. The present scheme provides a continuous tuning capability for changing the notch frequency. Measured notch rejection is greater than 40 dB. This scheme can operate over a wide wavelength range of the optical carrier. There is good agreement between experiment results and theoretical analysis.

Dispersion effect and compensation in optical-carrier-suppressed modulation transport systems

We develop new expressions for power fading and average power fading that are induced by first-order polarization mode dispersion, polarization-dependent chromatic dispersion, chromatic dispersion, and chirp under both (i) carrier suppressed modulation and (ii) odd-order optical sideband and carrier suppression. Experimental results show the effectiveness of the theoretical analysis. Further, based on the expressions, we propose a technique for optically compensating the polarization mode dispersion-induced power fading in carrier suppressed modulation.

Generating Odd-Order and Tunable Higher-Order Optical Sideband Suppressions with an Electro-Absorption Modulator

Odd-order and tunable higher-order optical sideband suppression modulations are demonstrated. The configuration is based on a Sagnac interferometer containing an electro- absorption modulator, a polarization controller, a time delay line and a variable polarization beam splitter.

Multiple Dual-Wavelengths Erbium-Doped Fiber Laser

A multiple dual-wavelengths erbium-doped fiber laser is demonstrated. More than 30 power equalized dual-wavelengths is achieved in 10 nm range. The switchability to normal multiple wavelengths laser is also discussed.

Multi-tap microwave photonic filter using a sampled-chirped fiber Bragg grating based multi-wavelength erbium-doped fiber laser

In this paper, we present and experimentally demonstrate a multi-tap microwave photonic filter. The filter is based on a multi-wavelength erbium-doped fiber laser which is inserted with a sample-chirped fiber Bragg grating. The near-Gaussian-profile multi-wavelength distribution is created for the fiber laser in order to generate the multi-tap filter. Reconfigurability feature of the filter is also demonstrated.

Microwave photonic notch filter with an electro-absorption modulator in a Sagnac fiber loop

Coherence-free microwave photonic filter configurations are presented. The configurations are based on a Sagnac loop interferometer containing an electro-absorption modulator (EAM) without a nonreciprocal bias unit. Notch responses are obtained by modulating the clockwise and counterclockwise propagating waves inside the Sagnac loop at different times. Measured results verify the theoretical expressions and demonstrate a robust notch filter response extending to high frequency without reducing notch depth.

Four-wave mixing assisted multiwavelength peak-power-equalized semiconductor optical amplifier laser

A four-wave mixing assisted multiwavelength semiconductor optical amplifier laser is experimentally demonstrated in a fiber ring cav- ity. A sampled linearly chirped fiber Bragg grating is used as the wavelength-selective component. Four-wave mixing enhances the num- ber of peak-power-equalized lasing wavelengths and operation stability of the ring laser. The extinction ratio of the 20 multiwavelengths output is greater than 40 dB, and the peak-power difference is less than 3 dB. ©

Simultaneous dual free spectral range microwave photonic filter using a high-birefringence chirped grating in a Sagnac loop.

We propose a continuously tunable, dual free spectral range (FSR) photonic microwave notch filter configuration using a high-birefringence linearly chirped fiber Bragg grating (Hi-Bi LCFBG) that is connected in a Sagnac loop using a Hi-Bi coupler. The configuration employs double sideband modulation and can generate two FSRs simultaneously. The larger FSR corresponds to the differential time delay of the Hi-Bi LCFBG and the Hi-Bi pigtails of the coupler; the smaller FSR corresponds to the time delay between the arms of the Sagnac loop. Measured results demonstrate dual FSR, a large notch rejection, and that the FSR is easily tunable by tuning the LCFBG. We also present the filter transfer function for the design. Experimental results agree well with the theoretical analysis.