Performance Evaluation for an Optical Fiber Link Millimeter-Wave Measurement System

We have already developed an optical fiber link millimeter-wave measurement system. The millimeter-wave measurement system consists of an optical fiber link millimeter-wave generator and an optical fiber link millimeter-wave receiver. The millimeter-wave generator and the millimeter-wave receiving system use an optical harmonic wave generation technique that consisting of a LiNbO3 optical intensity modulator, a sub-harmonic mixer and two photodiodes. In this paper, we show the performance of the millimeter-wave measurement system as a function of the optical harmonic generation characteristics for the input power and DC bias voltage of the LiNbO3 optical intensity modulator.

I. Introduction

We have already developed an optical fiber link millimeter-wave measurement system that consisting of a signal generator [1] and a receiver [2]. The generator consists of a LiNbO3 optical intensity (LN) modulator of T.MXH1.5-20PD-ADC-LV of Sumitomo Osaka Cement Co. Ltd. [3], a DC bias voltage for the LN modulator, a signal generator, and a uni-traveling carrier photodiode (UTCPD) [4]. The receiver consists of a sub-harmonic mixer of WR10SHM of VDI Inc. [5], the LN modulator, the DC bias voltage for the LN modulator, the signal generator, and a photodiode. In the case of inputting the electric signal to the LN modulator, the LN modulator generates n^th order harmonic waves of the optical frequency. The electric signal can generate the frequency of the electric signal as the frequency difference between an optical lower sideband frequency and an optical upper sideband frequency of the n^th order harmonic optical wave for the input frequency to the LN modulator. The generated n^th order harmonic optical wave intensity can control using the input DC bias voltage and the input electric power level to the LN modulator.