This section is to explain laser technology and features and put them into the context of the benefits they bring to the laser owner, operator and audience.
Understanding what's important
So that you can tell whether a laser has useful features or merely extra "bells and whistles", some basic understanding of the fundamentals of laser technology is useful.
- Most modern entertainment lasers are DPSS - the laser beams are produced by diodes. Improperly cooled diodes become noticeably dimmer during a night's use, and have much shorter life. Diodes may be replaced but represent a significant proportion of a laser's material costs. The sensitivy of the human eye varies with the frequency of light, so some colours appear brighter than others; the colour and power of a diode must be considered together. The apparent brightness of a laser display is also affected by the quality of the optics in the laser, how well maintained it is and how well the show has been programmed.
- The beams are aligned within the case to strike a pair of mirrors before leaving - these mirrors move to make the laser beam effects. Lower specification lasers move the mirrors with step motors, while higher specs use high-frequency galvanometer scanning mirrors; these are rated at the highest frequency at which they can respond. More responsive scanners are better able to draw complex shapes and animations smoothly.
- There are several control modes possible for a laser; some rely on effects built-into the laser, while at higher levels of control the laser responds to cues sent from an external controller (usually a software program). In Auto, Sound-Active & DMX modes, the laser runs through its built-in effects in response to its own programs, the sound in the room or a DMX lighting controller respectively. An ILDA DB25 connection uses an agreed communication standard to control the laser from a computer - but the laser must be capable of responding to it effectively; an ILDA connection is worthless on a laser with step motor scanners. USB interfaces are proprietary computer/laser connections that typically allow the laser to be controlled from a software program available from the laser manufacturer without additional hardware. The usefulness of a USB connection depends on the quality of software that supports it. There is really only one brand of significance in quality laser control - Pangolin.
Some of the key features of lasers explained:
- Output power
- Flex control
- Powered by Pangolin
- Scan system
- ILDA DB25 connector
- USB live control
- Master/slave linkable
Laser manufacturers often publish the power of a laser as the sum of the maximum rating of the diodes. Neo-Laser builds lasers to exceed a minimum output power and measures them to ensure it is met.
The human eye perceives colours differently, being more sensitive to green than the other laser colours. This means that green lasers look up to 4 times more powerful, and to produce a balanced white, much less green is required.
Thermal Electric Cooling is more efficient than air-cooling. More effective cooling keeps the laser bright for longer, broadens the temperature operating range and lengthens the life of the laser.
In-built workflow circuitry allowing you to run the laser by multiple control methods simultaneously
Pangolin is the world-renowned industry leader for laser control software and hardware.
A DMX interface allows the laser to be controlled with a standard lighting controller. The number of channels indicates the degree of control available. DMX connections may also be used for master/slave linking.
The sophistication of the scan system determines the how well a laser can display moving shapes and patterns, graphics and text
This standard 25-pin connector means the laser show can be programmed and controlled with industry-standard software such as Pangolin's Lasershow Designer or Live Pro.
A USB interface (along with control software supporting it) can give as much sophistication as the ILDA DB25 interface without an extra computer card. As well as saving money on hardware, this allows use of a laptop.
Blanking is shutting the laser beam off as required to draw images and effects. As a product feature, it usually refers to mechanical blocking or deflection of the beam (eg by a scanner).
Master/slave linking allows multiple units to coordinate their execution of built-in patterns and programs without requiring an external controller.
Modulation varies the intensity of the laser source and is used in colour mixing and the projection of sophisticated effects. Control over beam intensity varies from on/off for simple TTL, through 8-bit TTL to any variation with analog.
A product that is sound-active has built-in microphone and can respond to sound (eg. music) in executing built-in patterns and programs without an external controller.