LIDAR is an important technique for the measurement of range, velocity andvibration, as well as atmospheric parameters.In literature, direct detection, coherentheterodyne detection and coherent homodyne detection represent the main basic detectionstructures used in FMCW lidar system.We investigated the different detection techniquesespecially direct detection, coherent heterodyne detection and coherent homodyne detectionon FMCW lidar system using Optisystem package for the first time.A model for target,propagation channel and various detection techniques were developed using Optisystempackage.A comparative study among various detection techniques for FMCW lidar systemsis done analytically and simulated using the developed model.　　Through this work; the lidar receiver utilizes Mach-Zehender intensity (MZI)modulator for the first time and cooperated with a single photodetector for range andvelocity measurement.This overcomes the unbalanced photodetection problem of dualphotodetetor used in coherent detection and isnt affected by the phase diversity problemwhich faces the homodyne detection.　　Distance detection and Doppler detection based on MZI modulator cooperated withsingle photodetector are presented for FMCW lidar system.A mathematical analysis for bothproposed detection is introduced.Proposed distance and Doppler detection based on MZImodulator are modeled and simulated using Optisystem package.　　Performance analysis of both proposed detection is presented at different operatingpoints for MZI modulator especially quadrature point and null transmission point.Ananalytical comparison of both proposed distance detection and Doppler detection based onMZI modulator with traditional direct detection is presented through this work.　　The developed model using Optisystem package verifies the mathematical model ofboth proposed detection.The results demonstrate that the operation of proposed detectionbased on MZI modulator at null transmission point improves the range resolution by twoorders than other traditional detection techniques.In addition to the performance of proposeddistance detection based on MZI modulator achieved better performance than directdetection in thermal noise limited case.