The profile of common free output diode lasers is asymmetric (elliptic) Gaussian beam with a large divergence and nonuniform distribution. In most applications, it is necessary to shape and smooth the beam，there are two common shaping methods: optical lens shaping and fiber coupling shaping. Using lens could change the beam spot to rectangle but could not make it uniform , the space location for lens could not be removed flexibly. Using fibers, the output beam profile is rounded and uniform, the beam quality could improved, and the fiber coupling is an important means to realize flexible transmission which is popular in Medical, Industry areas. BWT Beijing has focused on fiber coupling diode lasers for over 15 years, and became the famous and professional manufacturers in international.

BWT‘s fiber coupled diode lasers can be divided into three categories: Single Emitter Diode Lasers, Mult-Single Emitter Diode Lasers, and Fiber Bundel Diode Lasers. Single Emitter Diode Lasers can provide the multi-wavelength covering from 405nm to 976nm, and the output power from 2mW to 10W. Multiple Single Emitter Diode Lasers are built upon the foundation of multi-emitter coupling technology to obtain the power reached to 200W and high brightness. Fiber bundel technology could bundel several diode lasers together and launch their beams into a single fiber via combiner, which could obtain the wavelength covering from 450nm to 1550nm and the power could reach to 300W.  Mult-Single Emitter Diode Lasers and Fiber Bundel Diode Lasers are the best options for high power diode lasers.

Fiber optic connectors come in a wide variety of types. In telecommunications, the mainstream types include FC, SC, ST, LC, MPO, and E2000: FC uses a threaded locking structure and offers excellent vibration resistance; combined with an APC endface, it is a preferred choice for precision optical paths. SC is push-pull and offers the greatest versatility. ST uses a bayonet mount. LC has a small ferrule and is suitable for high-density cabling. MPO can connect multiple fibers at once, making it suitable for parallel high-speed optical paths. E2000 has a square push-pull structure and comes with automatic dust and light-blocking caps at both ends, making the endface less susceptible to contamination. The field of laser power delivery has its own system: SMA905/906 and HP-SMA905/906 can cover low-, medium-, and high-power pump sources, medical lasers, industrial lighting, and specialty lighting scenarios; D80 has a higher power-handling capacity and is often equipped with water cooling for high-power transmission above the hundred-watt level; QBH can handle kilowatt-level high power and is mostly used for high-power direct diode lasers, fiber lasers, and connections in welding and cladding optical paths.

Generally, the center wavelength in BWT website is corresponding to the center of full width at half maximum height of the spectrum measured at a certain temperature and power. The full width at half maximum height refers to the wavelength difference at both side of spectrum pulse corresponding to the half intensity of the peak. The center wavelength is mainly determined by the semiconductor material and would be shifted with the base plate temperature and operating current.

The common cooling method is air cooling or water cooling. The required heat release for diode lasers could be calculated according to its output power and electric consumption. In general, single laser diode can be directly placed on the base plate with fans or TECs which is simple and easy to operate. For several high power diode lasers, water cooling plate is preferred, base plate with TECs and fans may be also available. 

Beside the high quality diode lasers, BWT also could offer rich kinds of accessories and complete solutions in lots of applications. Such as drivers, focused lens, collimators for scientific researches, solid settings for CTP printing, optical lens for illumination and imaging, and couplers, connectors for wide uses.

For drivers, we could offer the customization services in below:

A. Constant current drivers and constant output power drivers:

Constant current drivers: output the constant current to control the diode lasers;

Constant power drivers: adjust the current according to the feedback of Photo Diode to achieve the fixed output power.

B. The optional functions and appearances

Desktop version: the diode lasers, fiber coupling and heat dissipation are all integrated in a box. All the settings are displayed and adjustable on LCD panel.

OEM version: it is convenient for users to integrate the laser systems inside the instruments.

C. The optional operating modes(CW, pulsed and single pulsed mode)

CW, pulsed or single pulsed mode is optional, the pulsed mode is achieved by TTL modulation single, the voltage of TTL single is between 0-5V. The output synchronizing signal form systems is very convenient for some applications. 

1. Laser safety

Powerful laser radiation is dangerous, mainly for eyes and skin, don’t look at the laser beam straight, even wearing the laser goggles.

2. Electrostatic protection

The positive and negative pins must be shorted when the diode lasers are in transit or in storage. The Antistatic bracelet must be needed for the operator.

3. Avoid the electrical surge

A electrical surge is a sudden instantaneous electrical pulse, over high surge would break down PN junction and destroy the diode lasers. To avoid the electrical surge, the power supplier should be slowly started, and connected with diode lasers tightly. If the output power is adjustable via a potentiometer, it is better to use a current-limiting resistor in series with it.

4. The connection between pins and driver

For the operating current of >6A, please weld the pins to the wires of driver, the welding point should be close to the root of the pins as possible with the proper tension. To avoid damaging the diode lasers, please use the electric soldering iron with low power of <8W and temperature of <260℃，the welding time shall not over 10 seconds，at the same time, please offer the electrostatic protection.

5. Cleaning

Please clean the fiber end-face using the alcohol before turning on the laser to avoid reducing the output power or damaging the fiber. When the laser is not worked, please put the protected cap on the connector.

6.The fiber bend radius 
The maximum bend radius is recommended not less than 300 times of fiber cladding diameter.