Laser Diode Modules for Test Instrument are designed to convert electrical signal to optical signal and are suitable for application in long fibre optic link and test equipment. The Laser Diode Modules are efficient in providing very good energetic characteristics and have very low threshold and operating current. The Laser Diode Modules are based on InGaAsP laser diodes and provide a stable, single transverse mode oscillation with emission wavelength of 1310 nm and 1550 nm offering output power 2 MW. Laser Diode Modules for Test Instrument are hermetically sealed devices having the photodiodes for optical output monitoring and ensures high performance for long time.