Lasers will be the core devices of optical transceivers, which injecting current into semiconductor materials and injecting laser light through the photon oscillations and gains within the resonator. At the moment, the absolute most widely used lasers are VCSEL, FP, and DFB laser. The essential difference between them is that semiconductor materials and resonator structures. DFB lasers are more expensive than FP lasers. The optical modules of transmission distance within 40km generally use VCSEL, FP lasers; transmission distance ≥ 40km generally use DFB lasers. Have you any idea most of the transceiver laser types? Why don’t we learn this knowledge.
Light-emitting diode referred to as LED. Manufactured from a compound containing gallium (Ga), arsenic (As), phosphorus (P), nitrogen (N). Visible light is emitted when electrons recombine with holes and thus may be used to make light emitting diodes. In the circuit and equipment as a light, or made up of text or digital display. Gallium arsenide diode red, gallium phosphide diode green, silicon carbide diode yellow, gallium nitride diode blue. Due to the chemical nature of organic light-emitting diode OLED and inorganic light-emitting diode LED.
For optical fiber communication systems, LEDs will be the best source of light of choice if the multimode fiber is used in addition to bit rate is under 100-200Mb/s while only requiring input optical power of tens of microwatts. Compared with the semiconductor laser, because the LED does not require thermal stability and light stabilization circuit, so that the LED drive circuit is simple and easy, its production cost is low, high yield LED emission spectrum line light, poor directivity, its very own response speed Slow, so limited to the low speed communication system. The LED laser widely used in 155M 1×9 multimode transceivers.
Vertical-Cavity Surface-Emitting Laser (VCSEL) is a type of semiconductor laser whose laser is perpendicular to the top surface it really is made of an independent chip this is certainly generally cut with a slit, together with edge-emitting laser differs from the others from the edge-emitting laser. VCSELs typically use 850nm wavelengths for short-range transmission of Gigabit Ethernet to 10GbE SR multimode fiber.
VCSEL laser has many advantages over edge-beam lasers within the production process. Edge-beam lasers can not be tested after production. If an edge-emitting laser doesn’t work, it is a waste of processing time and material processing time, either as a result of poor contact or poor material growth. However, VCSEL can be tested its quality and troubleshoot any manufacturing process. For instance, if the paths amongst the dielectrics are not completely and cleanly connected, the most notable metal layer is not in contact with the test metal layer throughout the pre-packaged test additionally the test outcome is incorrect. Further, considering that the laser light emitted from the VCSEL is perpendicular towards the reaction zone, and edge emitting laser light emitted in parallel to the reaction zone contrary, there might be thousands of VCSEL to be processed on a three-inch large gallium arsenide chip simultaneously. In addition, even though VCSELs require more labor and finer material within the manufacturing process, more predictable production results could be controlled.