Laser in the 1.3 μm band is one of the important transmission windows of optical fiber. It has low loss (0.5 dB/km), dispersion close to 0, and can be transmitted over long distances in quartz fiber. It is one of the ideal light sources for laser fiber communication and here are important applications in the field of communications.
Theotry
The main components of device are:
Gain medium - Nd YAG
The Nd:YAG crystal has excellent physical and chemical properties, and has a high matrix hardness, good thermal conductivity, and good optical quality. In order to suppress the main transition wavelength and obtain a wavelength of 1.3 μm, plating a film on crystal pass-through surface to select wavelength.
V:YAG is a vanadium-doped yttrium aluminum garnet. It is a new material as laser-saturated absorbers and passive Q-switched switches in the wavelength range of 1.06 μm to 1.44 μm. It is especially suitable for 1.3 μm HeNe lasers. The saturation intensity in the 1.3 μm band is large, and the damage threshold is high, the recovery time is short, and the thermal stability is good, making it an excellent saturated absorber material in the 1.3 μm band.
Passive Q-switch：V：YAG
Mirror——M1 – input mirror. Anti-reflection for 808nm pump light, and high-reflective film for 1300nm – 1600nm. M2 – output mirror. Anti-reflection for 808nm, and it is half-reflective for 1300nm-1600nm.
The laser near the wavelength of 1.3μm is consistent with the wavelength of the low-dispersion and low-loss regions of the silicon fiber, which is consistent with the widely used silicon fiber transmission window in optical communication. Its double frequency is an effective way to obtain red laser, so 1.3μm Laser has broad application prospects in the field of optical fiber communication.
Feature
- Efficience of output is high
- High stability
- At atmospheric transmission window and fiber transmission window
- Small dispersion in the fiber
Application
- Light Source For Fiber Optic Communication Systems
The 1.3μm laser line, located in the low-loss, zero-dispersion window of quartz fiber transmission, is an ideal source for long-distance non-relay fiber-optic communication systems and multi-branch fiber-optic communication systems. The laser also has the characteristics of narrow spectra width, high power density, small thermal drift, small beam divergence angle, and easy to obtain single longitudinal mode laser output.
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