Laser FAQs

Please check out our Glossary section for definition of terms.

Optics

How does one measure line thickness?
StockerYale's low power laser line projectors have a pseudo-Gaussian widthwise intensity profile analogous to that of many gas lasers. The thickness (or width) of the line is measured at the 1/e^2 points of this profile. A chart of LINE THICKNESS VS PROJECTION DISTANCE can be found in many of our Laser data sheets and brochures. In order to guarantee accuracy, the values measured were carefully taken using a Merchantek beam profiler.

What is Depth-of-Field?
The depth-of-field is a measure of how well a focused line remains in focus within a specified range. It is commonly defined as twice the Rayleigh range which is the distance over which the line thickness increases from its minimum to a thickness equal to two times this minimum. See details in our glossary.

Why is the Depth-of-Field value useful?
This value will let the user know the range over which there is no appreciable change in line thickness.

What is a fan angle?
The fan angle or angular spread of the laser beam determines the length of the line produced at a certain projection distance given by the formula : L=2DTan(FA/2) where L=length of line, D=projection distance and FA=fan angle. StockeryYale offers you the choice of standard fan angles 1°, 5°, 10°, 20°, 30°, 45°, 60°, 75°, 90° and custom. Please note that the 1° fan angle is not available with the cross-hair model. See details in our glossary.

What is an inter-beam angle?
The inter-beam angle is the angular separation between any two lines, dots, or circles of our various projection heads. The inter-beam angle is given by the formula: q=sin^-1 (l/D) where D=period of the diffraction gratin, 1=wavelength and q=inter-beam angle. See details in our glossary.

How can I get a "cleaner"-looking laser pattern with my laser?
You can have the option of having a spatial filter installed on your laser.

What is the relationship between wavelength and temperature?
There is a wavelength drift of 0.25 nm/°C.

What is the difference between the Lasiris 501L and the
701L series of laser projectors?
The 501L will project the smallest line thickness. The 701L produces a thicker line but it has a better depth-of-field than the 501L.

Electronics

What is the synchro option?
The synchro option will allow you to externally modulate the laser with the use of a BNC cable as described below:

Digital modulation : The laser will operate at full output (100%) when 0 VDC is supplied to the BNC cable and the laser will be turned off (0%) when the voltage supplied to the BNC is 5 VDC. The frequency range is from DC to 10 KHz with a rise and fall time of 10 micro seconds and a 100% modulation depth. This option is recommended for asynchronous operation.
Analog modulation : An input signal ranging from 5 volts down to 0 volts will allow you to linearly control the optical output power from 0% up to 100%. For example, supplying a constant ~2.5 VDC to the BNC will set the output power to approximately 50% of its maximum value.

What is the Modulation option?
The Modulation option will also allow you to externally modulate the laser with the use of a BNC cable as described below:

Digital modulation : The laser will operate at full output (100%) when 0 VDC is supplied to the BNC cable and the laser will be turned off (0%) when the voltage supplied to the BNC is 5 VDC. The frequency range is from 6 Hz to 2 MHz with a rise and fall time of 30 nsecs and a 99% modulation depth. This option is not recommended for asynchronous operation, due to a stabilization delay of 1 second before the laser will produce a stable output. It is recommended for applications where a high frequency regular train of pulses is required.
Analog modulation : An input signal ranging from 5 volts down to 0 volts will allow you to linearly control the optical output power from 0% up to 100%. For example, supplying a constant ~2.5 VDC to the BNC will regulate the output power to approximately 50% of its maximum value.

What is the exact power output one can get from a 5, 10, 20, 30, and 50 mW laser module without a projection head?
The actual power of our lasers after collimating optics is as follows:

Diode Power (mW)		Standard Output Power (mW)

5		3.5
10		7
20		14
30		20
50		40

What are the current draws for our different laser modules?

Power		Current

1 mW		65 mA
5 mW		70 mA
10 mW		80 mA
20 mW		90 mA
30 mW		100 mA
50 mW		120 mA

Safety

What different Safety classes do Lasiris™ laser modules fall under?
Lasiris laser modules fall under the following safety classes:

class II : Caution; Visible laser light less than 1.0 mW. Considered eye safe, normal exposure to this type of beam will not cause permanent damage to the retina.
class IIIa : Danger; Visible laser light between 1.0 and 5.0 mW. Considered eye safe with caution. Focusing of this light into the eye could cause some damage.
class IIIb : Danger; Infrared (IR) & High power visible lasers considered dangerous to your retina if exposed.

For more details, please refer to the LASER SAFETY GUIDE, published by the Laser Instititute of America or click here.

What is the procedure for evaluating laser safety class according to FDA regulations?
Each laser is classified by measuring the amount of optical power that would enter a 7 mm aperture (i.e. typical eye opening) that is located at a distance of 20 cm from the laser source. It is for this reason that the classification of Lasiris™ structured light laser projectors are pattern dependent.

If the measured power is:

Less than 1 mW then the laser is classified class II
Between 1 and 5 mW then the laser is classified class IIIa
Greater than 5 mW then the laser is classified class IIIb

Please note that all IR lasers (wavelengths longer than 700 nm), no matter how little the power output, are always class IIIb.

Click here for details.

What is the difference in class rating between the DLS-500-635-5, dot projector and the SNF-501L-635-5-45° line projector?
The DLS-500-635-5 is rated a class IIIa laser since all of its optical power is concentrated within a single dot. Nearly all this power would enter a 7 mm aperture at a distance of 20 cm (see preceding question). The SNF-501L-635-5 45° is rated a class II since its optical power is spread throughout a line, so only a fraction of this power would enter a 7 mm aperture.

Will a SNF-501L-635-5 45° laser module without the 45° line projector head, still remain a class II laser?
No, this laser will be equivalent to a DLS-500-635-5 laser with a class IIIa rating. All Lasiris™ laser modules are class specified with projection heads on the laser.

Why do Lasiris line generators have lower class ratings than other line generators on the market with the same laser power?
Line generators from our competitors use cylindrical optics which generates a line having a Gaussian uniformity profile, bright in the center and fading out toward the ends. This center "hot spot" often has enough energy to push the laser into the next level of safety ratings. Since StockerYale uses a patented optical design (the Powell Lens) to generate a line of quasi-even intensity, there is no "hot spot" and therefore a lower class rating for your laser is observed. See the Lasiris Advantages page or the description about Gaussian uniformity profile on our Non-Gaussian Distribution page.

Who can supply proper laser protection glasses?
An American company called KENTEK can provide you with laser protection glasses. Their coordinates are : KENTEK, 19 Depot Street, Pittsfield, NH 03263, tel-603-435-7201, fax-603-435-7441.

Miscellaneous

How much power do I need at a certain distance away
from the target?
1 mW of laser power is required per foot of line away from the target for an alignment application.

Where can I find user manuals for my laser?
Your laser was shipped with an instruction manual showing you how to use your laser. In the event that you lose the manual or need an extra copy, either contact us for an extra one, or visit the manuals page.

What are the warranty terms?
All Lasiris lasers are guaranteed to be free from material and manufacturing defects for a period of at least one year, and many for two years. Should a product fail during this period, StockerYale will, at its discretion, repair or replace the damaged unit. Repaired or replacement units will be covered for the remainder of the original equipment warranty period. This warranty does not apply to units examined by StockerYale that are found to have failed due to customer abuse, acts of nature, mishandling, alteration, improper installation or negligence.

How can I return a unit for repair? (RMA)
In the event that you should experience a product failure, please click on the following link for return instructions.