عنوان مقاله [English]
Recently, there has been an exponential increase in the use of Free Space Optical (FSO) technology, mainly for high rate data transmission through secure communication channel with low probability of interception. Because of this method's advantages in military communications, this kind of communication systems can be used in the communication links’ between two ships or ships and coastal station data transmission applications. These systems work based on laser beams propagation through turbulent atmosphere including aerosols originated from sea surface affected links reliability. Generally, laser communication systems consist of two main subsystems, optical transmitter and receiver, which these subsystem’s design have a strong effects on link performance and effective range. Due to importance of optical receiver design, in this paper, optical design of the laser communication links’ receiver is analyzed. Initial beam divergence angle of laser source (in communication link (λ=1550 nm)) is about 10 degrees and is reduced to 2 mrad after the collimator. Effective aperture diameter of transmitter is about 8 mm. The effective communication link range is 10 km. Used Photodiode in receiver is Hybrid-H3 which is selected from Laser-Components Company catalogue. The diameter active area of this photodiode is equal to 500 micrometers. Receiver optic’s aperture diameter is 20 cm and their optical glass is SF6. This receiver can be fabricated in Iran. Receiver optical design simulation is done by ZEMAX software. To verify the system performance, some standard graphs of this software are analyzed.