laser designator指的是激光指示器。
laser sight指的是激光瞄準器。
例句比較：
laser designator
1、It is a meaningful thing to improve the test accuracy of laser designator.
對提高激光指示器參數檢測精度有著重要意義。
2、Semiconductor laser designator is widely used in small arms system because of itswell-orientation, visible and intuitive, which can realize the weapon system quickly aimed at close range.
半導體激光指示器由於方向性好、可見、直觀等特點，已廣泛應用於輕武器系統，實現武器系統近距離快速瞄準。
3、The completion of this laser designator simulator is of some significance toemulation research on semi-active laser guiding, laser countermeasure, laserreconnaissance and warning.
激光目標指示模擬器對開展激光半主動制導、激光對抗和激光偵察告警仿真試驗研究具有壹定意義。
laser sight
1、Protection performance against laser for a sight scope and biological effect.
觀瞄鏡防激光性能測試及生物效應實驗
2、The laser sight on the Blackbird's pistol lets me know that just as he pulls the trigger.
在山鳥類的槍上的雷射視力讓我知道，正如他拉板機。
3、Basic design 9mm semi-automatic gun. 12 shot clip. Long-range weapon. Optionalsilencer and laser sight.
基本設計為9毫米口徑半自動槍，12發，長射程。可選配消音器和激光瞄準器。