CO_2激光辐射的探测,在激光测距和风速测量等应用中日显重要。测距用脉冲激光器可直接接收,测风速要用连续激光器,须用外差接收。通常脉冲系统要求探测器的上升时间为50毫微秒或更短一些,亦即带宽为3～5兆赫,这种系统还要求接近背景限的高探测率。光导碲镉汞可以达到高D~*,利用少数载流子扫出也可达到要求的带宽。碲镉汞光电二极管也是适合的。然而,实际上作者并没有做出高D~*的光导探测器。外差系统要求带宽要宽,达100兆赫或更宽一些,只有光电二极管才能满足此要求。碲镉汞由于介电常数低,它在响应速度方面较 The detection of CO2 laser radiation is of paramount importance in applications such as laser ranging and wind speed measurement. Ranging pulse laser can be directly received, the wind speed to use a continuous laser, heterodyne to be received. Pulse systems typically require detectors with rise times of 50 nanoseconds or less, or 3 to 5 MHz of bandwidth. Such systems also require high detection rates close to the background limit. Light guide cadmium telluride Hg can reach high D ~ *, the use of minority carrier sweep can achieve the required bandwidth. HgCdTe photodiodes are also suitable. However, in fact, the author did not make a high D ~ * photoconductive detector. Heterodyne systems require a wide bandwidth, up to 100 MHz or wider, and only photodiodes can meet this requirement. HgCdTe is more responsive in terms of its low dielectric constant