2/28/2023 0 Comments Laser jump speedBy introducing a QW active region and a Fabry–Perot resonant cavity into the base region of an electrical transistor, electrical and optical gains can be obtained. The energy band structure of the device is shown in Figure 1. introduced TL as a new type of heterojunction bipolar transistor laser. This paper introduces and discusses methods that can improve the modulation performance of TL based on the abovementioned schemes. Although these shortcomings limit the application of TL, it has been reported that the modulation characteristics (including bandwidth, power, and transmission rate) of TL can be improved by optimizing the base structures (e.g., quantum well (QW)) and introducing intracavity photon-assisted tunneling and external auxiliary circuits. Further, numerous problems relating to long-wavelength InP- based TL need to be addressed before it is commercially used in optical fiber communication these problems include low mode gain and strong inter-valence band absorption in the base region. Among these is the fact that the power of TL is less than the commercially required level, which also limits its modulation capability (see Section 2.2). More research is needed on TL to address various issues. However, compared with DML, substantially less research has been conducted on TL. Therefore, TL is expected to replace DML in optical fiber communication. TL has the inherent advantage of short carrier lifetime, and the unique three-electrode structure increases the choice of modulation methods. It is difficult to overcome this limitation without the use of four-level pulse amplitude modulation or hetero-integrated structures such as substrate lift-off and die bonding. In the field of semiconductor lasers applied to fiber transmission (mainly in the 1310 nm and 1550 nm bands), conventional directly modulated lasers (DMLs) suffer from long carrier recombination lifetimes (approximately 1 ns) and serious carrier accumulation thus, the transmission rate of DML is limited to less than 50 Gb/s. This significant advantage has extraordinary application potential in the fields of fast optical logic gates and fast modulation. The carrier lifetime of TL in the active region is as low as 30–40 ps. In contrast to industrial semiconductor lasers (such as those for additive manufacturing, laser-foil-printing, and laser melting ), where the focus is on the electro-optical conversion efficiency, output power, and reliability, the primary focus for TL is modulation rate performance, with the goal of becoming the core light source device for next-generation high-speed communication systems. The transistor laser (TL) was the first electro-optical hybrid device that could output an optical signal and an electrical signal. Since the creation of transistors and lasers, numerous scientists have attempted to combine the electrical signals of transistors with the optical signals of lasers.
0 Comments
|
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
March 2023
Categories |