- An easy service.
- A high lifetime of more than 10000 hours.
- water-cooled laser head.
Current R&D status:
- May 2020 – checking with suppliers, preparing a full components list
- June 2020 – making a water pump + cooling system TEC (chiller)
- July 2020 – laser assembly
- August 2020 – output laser power measuring and all necessary tests.
- September 2020 – starting pre-orders.
Laser aligning process
Info about parts for the laser :
- Laser module – (side pumping ) – include pumping diodes, Nd:YAG rod. (Requires cooling water – approx 10 L / min, pressure approx 40 psi, water temperature stability 0,5°C.)
- Laser power supply – power supply for the laser module to operate manually and via PWM.
- Laser galvanometer – for fast engraving of small surfaces + YAG lens – this is part of the galvanometer.
- Laser path – base for mounting laser module, mirror holders, Q-Switch, galvanometer/welding head.
- Control card – operating power supply and galvanometer.
- Welding head – for stabile manual focusing beam.
- Beam expander – expanding beam will increase the lifetime of mirrors in the welding head/ galvanometer, and the fat beam can be better focused.
- Indication laser – for setting the position of the laser module, mirrors, etc.
- Total reflecting mirror – will be at the end of the laser module (part of the laser cavity).
- Partially reflecting mirror (front side of the cavity ) – one for CW operation, one for pulse operation with Q switch.
- Q-switch crystal – TBD with different initial transmissivity.
High average power, side-pumped passively Q-switched laser of 1064 nm by using composite crystal Nd: YAG/Cr4+: YAG/YAG
The experiment setup is shown in Fig. 1. The resonant cavity is a plane-plane structure, and it consists of a highly reflective flat mirror M1, a side-pump system and a partially reflective flat output coupler mirror M2. Both the diameter of mirror M1 and M2 are 20 mm. Then, M1 is coated with high reflection at 1,064 nm. The transmission (T) at 1,064 nm of
M2 is 10 %, 20 % and 35 %, respectively. The length of the resonant cavity is 90 mm.
The diameter of the composite crystal is 3 mm with a length of 65 mm. The length of Nd: YAG crystal is 61 mm, the length of Cr4+: YAG and nondoped YAG are 2 mm, respectively. The Nd: YAG is doped with 1.0 at.% of Nd3+ ions and the initial transmission (T0) of Cr4+: YAG is 80 %. For improving the output efficiency, both sides of the composite crystal are coated with an antireflection film of 1,064 nm.
High average output power passively Q-switched LD side-pumped laser by using Nd:YAG/Cr:YAG/YAG composite crystal
In this paper, a linear resonant cavity and LD side-pumped system with the Nd:YAG/Cr:YAG/YAG composite crystal rod and KTP crystal is applied to realize high average output power at 1064 nm and 532 nm. The initial transmission (T0) of Cr:YAG is 85%. The maximum average 1064 nm output power of 85.6 W is obtained when the optical pump power is 187.5 W. A II-Type phase matching KTP crystal is used as the nonlinear frequency doubling. And under the same optical pump power, 27.2 W average output power at 532 nm is achieved, corresponding the pulse width of 210 ns and the repetition rate of 21.2 kHz. The optical-to-optical efficiency is up to 14.72%.
The experimental structure of 1064 nm laser is shown as Fig.2. The distance from M1 to M2 is 90 mm. The maximum electrical power of the side-pumped module is 625 W (from GT OPTIC CO., LTD) and its electrical-optical conversion efficiency is up to 30%. The crystal in our experiment is the composite Nd:YAG/Cr:YAG/YAG. The total length and the diameter of the composite crystal rod are 65 mm and 3 mm (grown by FUZHOU GATHERLIGHT OPTOELECTRONIC CO., LTD), respectively.
The length of Nd:YAG doped 1.0 at.% of Nd3+ ions is 61 mm, the length of Cr:YAG (T0=85%) is 2 mm and the length of YAG is 2 mm. In order to obtain better results, both sides of the composite crystal are coated with antireflection coatings of 1064 nm. A plane mirror M1 is coated with high reflection at 1064 nm and 532 nm, and a plane mirror M2 is an output coupling mirror of 1064 nm with the transmission of T =10%.
Projected water cooling system
Diameter of YAG rod (mm) : 3
Diameter of YAG rod (mm):65
Standard operating current: 18A(16-22a)
Threshold current: 7.5a (6-9a)
Drive voltage: maximum 18V
Drive current: maximum 23A
Output power (W) : 50
Operating current (A) : 18
LD offset (V) : less than 18
Laser beam expander
Nd:YAG Dual wavelength 1064-532nm tunable beam expander is Galilean type telescope with 1.5- 5X magnification, which allows compact design for using in industrial environment. It features lenses are air spaced, thus expanders are suitable for high power applications. Standard beam expanders are designed for four most popular lasers: Nd:YAG; Ti:Sapphire; Yb:KGW and Yb:YAG, but custom wavelengths are available. Standard mounting thread is M27x1, which is compatible with common 4-axis mounts.