Products » Laser Subsystems

Laser Subsystems

In addition to being a supplier of high repetition rate TE CO₂ lasers, SDILasers also manufacturer several laser sub-systems that can be fitted to not only its own lasers but also other TE CO₂ lasers. These laser subsystems have been specifically developed for the industrial market to improve reliability, lifetime, performance, and running costs of CO₂ laser systems.

These options are discussed in greater detail below:

Agile Tuner: At SDILasers we have developed an agile grating control system that can be fully integrated into our laser control. In this system, a rotating mirror selects the wavelengths based on user-defined selections. The switch over time between the wavelengths selected allows single pulse wavelength selection at repetition rates up to 100Hz. The system is controlled via a Windows type interface, and is seamlessly integrated into our laser control. Menu options allow the user to specify recipe type operations.

This system is recommended for DIAL applications where transition time between multiple lines has to be minimised.

Part Number	AGT-30	AGT-40	AGT-50
Optical Radius	30mm	40mm	50mm
Max Repetition Rate	100Hz	100Hz	50Hz

Solid-state switching: SDILasers utilise thyratron based switching gear to transfer the high voltage pulse to the discharge volume of the laser. This switching gear can be replaced by a thyristor or IGBT based system. This system is much more reliable but requires a pulse transformer and pulse compressor to generate a high enough voltage for the discharge. As a result the system occupies a larger volume.

This system is recommended for lasers running at high repetition rates for extended periods of time.

Part Number	SSS5	SSS15	SSS30
Charging Voltage	5kV	5kV	5kV
Output Voltage	~40kV	~40kV	~40kV
Pulse Energy	5J	15J	30J
Repetition Rate	500Hz	500Hz	300Hz

Sidearm Catalyst: All our lasers come equipped with internal catalyst to prolong the gas lifetime. The catalyst is used to recombine the small amounts of CO and O₂ created in the discharge so that the gain of the laser does not decrease over time. This ensures that the laser can run on a single gas load for more than 10⁸ shots. However, for lasers requiring an even longer period between gas loads, a sidearm catalyst is recommended. This is an independent ancillary system outside the laser that can be coupled to the laser vessel. This enables the laser gas to be heated, thereby improving the efficiency of the conversion process and increasing the lifetime of the catalysts.

This system is recommended for lasers running at high repetition rates for extended periods of time.

Part Number	SAC-AM-250	SAC-AM-500	SAC-AM-700	SAC-HP-500
Operating Pressure	1Bar	1Bar	1Bar	8Bar
Gas Flow	250l.min-1	500l.min-1	700l.min-1	500l.min-1
O2 concentration	<1000ppm	<2000ppm	<3000ppm	<2000ppm

Gas flow system: In certain circumstances a client may request a gas flow system due to the gas mixture being used, typically for lasers with pulselengths in excess of 2μs, or due to the fact that the laser is operating at very low repetition rates for short periods of time. In such cases the internal catalysts are removed and a gas flow system is installed. This system is recommended for lasers running at low repetition rates or for high power lasers with long pulselengths using self-catalytic gas mixtures.

Gratings: The lasers come equipped with an output coupler and a back reflector. This resonator configuration results in the generation of a laser beam with a wavelength of 10,6μm. This is the 10P20 vibrational line of the CO₂ spectrum due to the fact that this line has the highest gain of all the vibrational lines. If the other vibrational lines in the emission spectrum between 9 and 11μm need to be accessed, a wavelength tuning component needs to be inserted in the resonator. We recommend the use of an original ruled grating which enables the user to tune between all the accessible line in the spectrum. This system is recommended for applications where lines other than the 10P20 need to be accessed.

Single longitudinal mode (SLM): Under normal circumstances an atmospheric CO₂ laser has a bandwidth of 300 to 400MHz due to the gain curve being wide enough to allow lasing from several longitudinal modes. For certain applications this bandwidth needs to be narrowed and this is accomplished by improving the gain of one of the longitudinal modes, hence the SLM operation. This can be achieved by seeding the resonator with a cw CO₂ laser or a diode laser, a low gain cell, or an intracavity etalon. Depending on the laser and the clients requirements the most suitable option will be recommended.

This system is recommended for applications where a very narrow bandwidth is required.

Automatic Alignment: SDILasers utilises a state of the art stable resonator to ensure long term stability and reliable output. In situations where the laser is used in a dynamic environment, like the back if a vehicle, an automatic alignment system can be added to the laser. This system gives the user the ability to either align the system remotely or allow the control system to continuously measure and update the alignment of the system.

This system is recommended for lasers that are being used in a dynamic environment or in an industrial environment where the lasers may be hard to access.

Beam shaping: The standard configuration of our lasers delivers a square multimode pulse with a divergence of >4mRad. For certain applications the client may require a specific beam shape or a beam with a low divergence. This can be accomplished by using an intracavity aperture to generate a Gaussian or TEM_oo beam that has a divergence of <2mRad. However, this configuration limits the amount of energy that can be extracted from the discharge volume. Where the client requires more energy we can replace the back mirror with a diffractive optical element or DOE that will generate a top hat profile thereby improving the energy extraction and minimising the divergence.

This system is recommended for paint stripping and non-destructive testing applications where maximum energy extraction and minimum divergence is required.