Fushen Chen

Integrated Optical Electric Field Sensor From 10 kHz to 18 GHz

A lithium niobate (LiNbO3 )-based integrated optical sensor with Mach-Zehnder optical waveguide interferometer and tapered antenna array was designed and fabricated for electric field detection. Experimental results reveal that this sensor has a frequency response deviation less than ±10 dB within the range of 10 kHz to 18 GHz, and its minimum detectable electric field intensity is 0.4 V/m. Moreover, a pulsed electric field with nanoseconds width and electric field intensity of 103 V/m have been detected by this sensor.

A Novel Bias Angle Control System for

A novel bias angle control technique to improve the performances of lithium niobate photonic E-field sensor while not disturbing the measured electric field has been demonstrated. Using this technique, bias locking at linear position along the transfer function is achieved with better than 2.2° accuracy. In addition, this bias control technique has been proven to be robust and simple to implement in field applications.

{\rm LiNbO}_{3}

A lithium niobate (LiNbO3)-based integrated optical E-field sensor utilizing Mach-Zehnder optical waveguide interferometer and bow-tie antenna has been designed and fabricated for the detection of nanosecond intense pulsed electric field. Experimental data demonstrate that the average rise time, fall time, and pulsewidth of the input/output electromagnetic pulse (EMP) are 1.31/1.28, 3.63/3.61, and 34.19/34.25 ns, respectively. Correspondingly, the relative errors are 2.3%, 0.6%, and 0.2%, respectively. In addition, the input/output of the sensor system shows a linear relationship as the correlation coefficient between measured and fitting is 0.9991. The minimum and maximum measured EMP fields are approximately equal to 3 and 50 kV/m, respectively.

Photonic Sensor Using Wavelength Tuning

A 3D lithium niobate integrated electro-optical electric field (E-field) sensor utilizing three optical waveguide Mach-Zehnder interferometers has been designed, fabricated, and characterized for the measurement of lightning electromagnetic impulse (EMP). The linear detected E-fields with the sensor are 15-370 kV/m. Experimental results demonstrate that the half wave E-fields of the 3D probe are all more than 4000 kV/m which means the maximal detectable E-field can be exceed 1000 kV/m. Based on the time domain response for applying the nanosecond EMP, the frequency response of the sensor has been calculated up to 500 MHz.

Integrated Optical

We propose and simulate an all-optical tunable notch filter based on a sum-frequency generation process in a periodically poled lithium niobate (PPLN) waveguide. The central wavelength of the filter can be tuned by adjusting the wavelength of input pump light. The maximum signal suppression at the central wavelength can be also changed by varying the power of input pump light. A maximum signal depletion of up to 34.4 dB is achieved when the central wavelength is tuned at 1545 nm. The simulation results show that this nonlinear optical filter owns a wide tuning range and steady 3-dB bandwidth on different signal power and wavelength values under low input pump power.

E

Abstract. A lithium niobate optical waveguide-based integrated electro-optic (EO) electric field (E-field) sensor dedicated to the measurement of intense nanosecond transient electromagnetic pulse (EMP) signals has been developed and calibrated. The time domain calibration system for measurement of intense nanosecond EMP signals has been established. A pure optical bias phase angle control system based on wavelength tuning has been developed and implemented to ensure that the sensor has a linear transfer function. The fluctuations of the sensor static output optical power are <0.1  dB with the proposed bias control system while >3  dB without bias control. The time domain characteristics of the detected pulsed E-fields have been compared with those of the input EMP signals. For the first type nanosecond level (ns-level) EMP signal, the relative errors of the detected E-fields on rise time, fall time, and pulse width are 0.38%, 0.69%, and 0.79%, respectively. Also, for the second type ns-level EMP signal, the relative errors of the measured E-fields on rise time, fall time, and pulse width are 0.40%, 0.31%, and 0.01%, respectively. All these results demonstrate that the developed integrated EO E-field sensing system has the potential to be used to accurately extract the information of transient E-fields.

-Field Sensor for Intense Nanosecond Electromagnetic Pulse Measurement

A new type of integrated optical magnetic field sensor is presented in this paper. The proposed sensor consists of a Mach-Zehnder waveguide interferometer and a doubly loaded loop antenna. Such a structure can successfully avoid detection of the undesired electric field signal. The size of the sensor is 35 mm×6 mm×1 mm. The measurements show that the frequency response is from 2 kHz to 9 GHz, the dynamic range is 98 dB, and the minimum detectable magnetic field is 51.8 μA/m at 1 GHz. Therefore, this sensing system can be used in electromagnetic compatibility measurements.

3D Integrated Optical E-Field Sensor for Lightning Electromagnetic Impulse Measurement

A tunable optoelectronic oscillator (OEO), which achieves stimulated Brillouin scattering (SBS) by injecting a pump laser into an upper single sideband (USSB) modulated signal, is designed. Through simply adjusting the wavelength of the pump laser, the frequency tunability of the OEO is realized. An experiment is performed. A microwave signal with a frequency-tuning from 2.4 to 10.765 GHz is generated, and the power is at least 38 dB higher than its harmonic components for all the frequencies. In addition, the single-sideband phase noise of the generated microwave signal is also investigated.

Investigation of All-Optical Tunable Notch Filter Based on Sum-Frequency Generation in a PPLN Waveguide

A Lithium niobate (LiNbO3) optical waveguide three-axis electric field sensor has been designed, fabricated, installed and measured. Experimental results reveal that the variation of the sensor frequency response is no more than ±3 dB from 100 kHz to 1 GHz. The output of the sensing system exhibits a linear function of the applied electric field varying from 2.2 kV/m to 56.8 kV/m. The time domain response of the sensor agrees well with the incident electric field. All these results demonstrate that the proposed sensor has a possibility to be used to detect the intense electromagnetic pulse (EMP) field.

Nanosecond transient electric field measurement system using an integrated electro-optic sensor

Abstract. We present the performance analysis of a spectral amplitude code labeled system with 100  Gb/s polarization division multiplexed (PDM) differential quadrature phase shift keying payload in simulation. Direct detection is chosen to demodulate the PDM payload by applying a polarization tracker, while 4-bits of the 156 Mb/s spectral amplitude code label is coherently detected with a scheme of frequency-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. For back-to-back system and 96 km transmission, label eye opening factors are 0.95 and 0.94, respectively, while payload optical signal-to-noise ratios are 20.6 dB and 22.0 dB, and the payload received optical powers are −15.0  dBm and −14.5  dBm for a bit error rate value of 10−9. The results show that both the payload and label have good transmission performances after long-haul transmission in a standard single mode fiber and dispersion compensating fiber, and the payload could be well demodulated after 288 km transmission.