Research On Optical Vector Analysis Using Photonics-Based Frequency Conversion

Ultra-large-capacity optical communication,ultra-high-precision optical sensing,and ultra-highspeed optical signal processing require optical devices,optical systems,or photonic chips to manipulate the multidimensional parameters of optical signals with high precision,such as amplitude,phase,and polarization.During the design,development and application of these high-performance optical devices,optical systems or photonic chips,it is necessary to accurately measure their multidimensional(amplitude,phase,etc.)frequency response.However,the traditional optical vector analysis(OVA)technology has key technical problems such as complex extraction of optical amplitude and phase,small dynamic range,and large non-linear errors.Therefore,it is urgent to carry out research on the new OVA technology to support and guarantee the preparation,production and application of advanced photonic devices and integrated chips,and lay the foundation for innovation and breakthroughs in related fields.This thesis focuses on the OVA using photonics-based frequency conversion.The traditional OVA is faced with complex extraction of optical amplitude and phase,large non-linear errors,and small dynamic range.The work is as follows:In order to solve the problems of complex extraction of optical amplitude and phase and large nonlinear errors,an OVA using dual-wavelength sweeping and photonics-based frequency downconversion is proposed.Photonics-based frequency down-conversion is used to convert high-speed photoelectric detection and ultra-wideband amplitude-phase detection into low-speed photoelectric detection and low-frequency microwave amplitude and phase detection,which greatly reduces the complexity of the optical amplitude and phase extraction unit.At the same time,this method avoids introducing non-linear errors.The experiment accurately measured the frequency response with the resolution of 1 MHz and the measurement bandwidth of 45 GHz by a low-speed photodetector at 10 MHz and a low-frequency amplitude-phase receiver.In addition,an OVA using acousto-optic frequency shift and photonics-based frequency down-conversion is proposed,which greatly simplifies the structure of the OVA system.In order to solve the issue of small dynamic range,an OVA based on harmonic detection was proposed.Compared with the traditional modulation phase shift method,the dynamic range is effectively improved.A non-linear error analysis model for OVA based on harmonic detection is established,and theoretical analysis and numerical simulation are performed.The results show that the OVA based on harmonic detection has smaller non-linear errors and larger dynamic range than the traditional modulation phase shift method.In addition,the engineering research of OVA based on harmonic detection is also carried out.The hardware design of the drive circuit board and the software design of the system control program are completed,and the principle prototype is built.The prototype can measure the frequency response of optical devices with the measurement bandwidth covering the C-band(1530 ? 1565 nm),dynamic range greater than 70 d B,and delay accuracy better than 1 ps.In summary,this thesis proposes OVA using photonics-based frequency conversion,which effectively solve the problems of complex extraction of optical amplitude and phase,large non-linear errors,and small dynamic range in the traditional OVA.It can lay the foundation of measurement technology for the research of new photonic chips and high-performance microwave photonic devices in the frontier field,thus strongly supporting the discovery and demonstration of new laws,new phenomena and new principles in the optical field.