Although there are many different types of light sources, Fiber Optic Splice Closure usually just use either LED(light emitting diodes) or laser diodes (LD) because of the requirements as stated above. LEDs and LDs feature small size, high power efficiency and many other beneficial features.
Because spontaneous emission is random and appears along all directions, the output from an LED is not directional. Output beam angles may be typically in the range of 30° perpendicular to the junction, to about 120° parallel to the junction.
SFP stands for Small Form-factor Pluggable is a hot-pluggable fiber transceiver. The mechanical, electronic, and optical design and performance are based on a Multisource Agreement (MSA) in the fiber telecom industry.
The MSA is an agreement among fiber optic industry leaders including Agilent, IBM, Lucent, Infineon, Tyco, Molex, Finisar, etc. The specification is maintained by the SFP committee.
SFP specification is compliant with GR-253-CORE, ITU-T G.957, SFF-8472, etc. It provides a fully standard compliant interface between the photonic layer and the electrical layer.
The main parts in a transceiver include a FP laser (or uncooled DFB laser), a PIN optical receiver with TIA built in, a post amplifier, a laser driver, and a microprocessor.
The structure of bulk fiber optical cables has many important characteristics. The fiber cable construction needs to provide protection from outside environment during its installation and throughout the fiber cable's working life time. Fiber Optic Splice Closure: http://www.greentelftth.com/product/fiber-optical-splice-closure/