Edit: The Optotronics unit in this review is apparently defective, possibly from shipping. This review will be updated when a new unit arrives.
This is a detailed one-on-one comparison of the Optotronics Premium +150mW Green Laser against the Novalasers X100 Compact Portable Laser.
Both of these lasers are 532nm green pointers that cost about the same, $196 USD for the Optotronics and $209 USD for the Novalasers. Both Novalasers and Optotronics are regarded as being high quality products, so I thought it would be interesting to compare the lasers against each other.
---------------
We'll start with a comparison of specs.
Optotronics Specs:
IR filter Coatings block >96% of all IR
Laser diode power 1000mW
Average Output Power > 150mW
Laser diode lifetime 5,000 hours MTTF
Beam Diameter (1/e2) <1.5 mm
Beam divergence <1.2 mrad
M2Beam Quality <1.1
Duty cycle @ 21 °C 60/60 sec on/off
Operating temperature 15°C to 30°C
Warranty 90 days
Novalasers Specs:
IR Filter Built-in, 99.5%
Pump Diode 808nm 500mW
Average Output Power > 100mW
Expected Lifetime 3000-5000 hours
Beam Diameter <1.0 mm
Beam Divergence <1.2 mRad
Recommended Duty Cycle 100 sec ON/10 sec OFF
Operating Temperature 15-30 degrees C
Warranty 3 months
These specs are from: Optotronics Green Pen Pointers
and Untitled Page respectively.
The factors that one looks to immediately are average output power, beam diameter, and beam divergence. The Optotronics boasts an output power 50% higher than the Novalasers. But with the smaller beam diameter on the Novalasers, the Novalasers unit actually has an irradiance 50% higher than the Optotronics! This higher irradiance results in a more visible beam as well as better burning power. The divergences of the beams are listed as being the same. Neither company claims their lasers operate in TEM00. More on that later.
Note also that the Novalasers product boasts better IR filtering, and (if it is to be believed, a better duty cycle: I tend to stay well under duty cycles to preserve the integrity of my units.)
Both lasers I received were overspec. The Optotronics laser came with instructions that had "verified 171mW 8/2/2010" written by hand at the top. But it is not clear if this refers to peak or average power. The Novalasers had a printed label stating: "Tested Average Power 115.3mW. Tested Peak: 136mW." The Novalasers product gets points for including both power ratings, not just one unspecified rating. It should be noted that for $30.00 more, one can get a detailed power over time chart from Optotronics detailing a laser's performance. I did not want to pay $30.00 more.
------------
Power.
I do not have a laser power meter to check the power, although I can probably get my hands on one for a test. If I do, I will update this post.
-----------
Irradiance.
Both lasers are very bright at night, with the Novalasers product having a somewhat "greener" beam. This is difficult to capture photographically, and I do not have a picture to illustrate this. I inerpret this "greener" appearance to be due to its higher irradiance. Irradiance is defined to be power per unit area, and thus varies with the distance from the collimation lens of the laser, as the diameter changes with distance. The irradiance decreases with distance (at least past the beam waist).
Since I do not know the actual average power of the Optotronics product, I use the minimum average power of 150mW for calculating the irradiance of the Optotronics laser and the minimum average power of 100mW for the Novalasers laser. (The actual irradiances are naturally somewhat higher.)
Irradiance = Power/Area.
Optotronics laser Irradiance = 150mW/(Pi *(.75mm)^2) = 8.488 W/cm^2.
Actually the above calculation of the Optotronics irradiance is not to be taken to seriously as the beam is not circular, as it does not seem to operate in TEM00.
Novalasers laser Irradiance = 100mw/(Pi*(1mm)^2) = 12.323 W/cm^2.
Thus Novalasers irradiance/Optotronics Irradiance = 1.5. In other words, the irradiance of the Novalasers laser is 50% higher than the Optotronics laser. (EDIT at close range.)
This is dramatically illustrated by the following video in which the lasers fight a book match:
You might wonder if the batteries were a factor in the above test. This was not the case as I measured the batteries immediately after the test:
I notice a lot of people on this forum focus mainly on the output power of their lasers. Since many of the same people are concerned about beam visibility and burning power, they should be more interested in irradiance, not power. Cutting the beam diameter in half increases the irradiance by a factor of 4. Doubling the power only increases the irradiance by a factor of 2. Naturally lenses can be used to focus a beam and obtain a smaller beam diameter, but it is distinctly less impressive to have to put a lens in front of your laser to achieve ignition. Irradiance is the key, not power.
For both of these lasers I am assuming that the lenses in the lasers are collimation lenses and that the beam waist is near the exit point on the front of the lasers. Visual inspection of the beams seems to bear this out. I have been able to light matches with the Novalasers unit from over 10 cm, but I have never been able to light any match with the Optotronics laser at any distance. (I can with a focusing lens, however.)
Remark1: Some inexpensive burning lasers available have lenses that focus the beam near the front of the laser to make dramatic burning easy. This does not seem to be the case with the Novalasers unit. Such lenses usually result in bad divergence a little further away. The Novalasers unit has a spot size at long range that is about the same size as the Optotronics unit.
Remark2: Some inexpensive burning lasers have high IR emissions that aid in burning. If the IR filter specs on the Novalasers unit is correct, it is not burning through its IR emissions.
Burning and beam visibility (irradiance): Advantage Novalasers!
--------------------
Divergence.
I have not yet been able to make a careful measurement of beam divergence for these lasers. This is due to my not having access to a beam profiler, nor had a chance to measure beam diameters past a known far field range. Note, beam diameter measurements made at distances closer than the far field distance are unreliable. In general the far field distance for a laser is given by the formula
Far Field Distance = 100 * d^2/lambda, where d is the diameter of the output aperture and lambda is the wavelength.
For these lasers, I do not know the output apertures, so I don't know the reliable distance for making diameter measurements. Any suggestions on the correct values to use for output apertures for these lasers would be helpful.
Taking the company specs. at face value, one concludes that they have similar divergence behavior.
Advantage: tie.
--------------
Mode behavior.
The Optotronics laser operates consistently in TEM01 (or TEM10, depending on how the laser is rotated.) Here is a picture of the Optotronics beam after 33.3 meters:
I have never seen the Optotronics laser to operate in TEM00. Here is a video of the beam spot at closer range (about 1m with the beam spread through a simple magnification lens):
The Novalasers laser mode hops between TEM00 and TEM01. Here is a shot of the beam at 33.3m operating at TEM00:
Here it is at the same distance operating at TEM01:
Here is a video of the Novalasers unit under operation (with the beam spread through a simple magnification lens) that shows the TEM00 spot:
In general, I have found the behavior of the the Novalasers beam to be quite unpredictable. On some days it seems to stay TEM00, while on others it hops to TEM01 after a few seconds. I have not yet determined the factors which control the mode hopping.
From the above picture, the TEM01 on the Optotronics seems rather muddy; one suspects that several modes are present. The TEM01 on the Novalasers unit seems to be a rather classics double Gaussian image. (The TEM00 on the Novalasers unit also seems to be a rather clear Gaussian image as well.)
Neither company specs their lasers to be TEM00, and Novalasers even states in their printed specs that the beam is multimode. Optotronics makes no mention of mode in their specs.
Mode behavior: Advantage Novalasers!
-----------------
Duty Cycles
Both laser companies give duty cycle information, which is typically missing from lower quality companies. The Novalasers lists a longer duty cycle, with shorter cool-down. Novalasers duty cycle: 100 seconds on / 10 seconds off. Optotronics duty cycle: 60 seconds on/ 60 seconds off.
But I must add that I always stay below duty cycle on-time to avoid damaging my units.
Advantage: Novalasers!
------------------
Host Quality
Aesthetically I like the look of the Novalasers host over the New Wish style host of the Optotronics device. I find the New Wish hosts to have the perennial problem where the internal battery contact spring slips into contact with the outer host and shorts the batteries. This has happened to every laser I have owned with this kind of host, including the Optotronics laser.
I have never had this problem occur with the Novalasers host.
It should also be noted that the Novalasers host has a removable front opening, enabling one to clean the lens, or add accessories. This is not the case with the Optotronics host.
Advantage: Novalasers by a long shot!
--------------
Supplied documentation.
The Optotronics unit came with two little slips of paper giving battery insertion instructions and an over voltage warning. The battery instructions had the power scrawled at the top.
The Novalasers unit came with a zip-lock bag containing four full sheets of paper of instructions and information, including peak power, average power, serial number, legal issues involving laser use, and the specs.
Advantage: Novalasers!
--------------
Packaging and Shipping
Both were well packed, although the Novalasers laser storage box was wrapped loosely in bubble wrap which was contained in another larger box, which also containing the instruction sheets. Also the Novalasers host box is filled with a dense foam which seems to offer more protection than the host box of the Optotronics unit.
The Optotronics unit was contained in its storage box, which was wrapped in bubble wrap, then shipped in a padded envelope.
Both units were shipped quickly, the Novalasers unit in two days and the Optotronics unit in one day.
Advantage shipping: Optotronics
Advantage packaging: Novalasers
----------------------
Subjective feelings.
Quite simply, I am disappointed by the Optotronics laser. I have had the Novalasers unit for about a month now and the Optotronics unit for only about a week, but after experimenting with both, I am decidedly much more impressed with the Novalasers unit. Optotronics gives a power rating, but doesn't state whether it is peak power or average power. For my unit it only says "Verified 171 mW". Is that peak or average? The website doesn't make that clear, although from the example given on the website, one would think it means peak power. This should be made more clear.
Novalasers, while having a small offering on their website, seems specifically targeted to serious hobbyists as well as educators. Both companies have similar prices and warranties for similar products, although Optotronics has many more products available, including serious lab units.
Finally I want to say, that this comparison is based on only one unit from each company, so it is definitely not a large enough sample for a real comparison of companies. It is just my experience with similar units at about the same cost from both companies. The companies seem to have somewhat different markets anyway.
-------------
A question for forum members based on the above review.
Does anyone here know of a company that sells a portable 532nm laser with 100% duty cycle, a collimated beam diameter < 1mm, with power of 150mW or greater? Please don't bother replying with any links that do not meet all three criteria.
I looked over the offerings of companies listed here as being high quality, and didn't see any with such an offering, although I might have missed something.
I may just have to build one myself. It seems that one could start with a diode and lens assembly from one of the Novalasers Alpha HP series and put them into a better host with exceptional cooling to obtain such a portable laser. But I don't know which diodes and lenses are used for these lasers. I also don't know if such a thing is possible with the particular diode used in the Alpha HP lasers; the diode can might heat up too fast for any cooling to make a 100% duty cycle possible. Also, I don't know anything about advanced cooling in hosts.
Any suggestions or thought would be welcome. Thanks!
-------------
About me.
I am a educator and professional technical person in a different field from laser technology, although I have had training as a laser technician in the past. I consider myself a laser hobbyist and have been using lasers since high school (then college physics lab units), but have only recently purchased some of the nice diode/DPSS units that have lately become readily available. I look forward to building and experimenting with many more lasers in the future. This is my first post on any laser hobbyist forum.
This is a detailed one-on-one comparison of the Optotronics Premium +150mW Green Laser against the Novalasers X100 Compact Portable Laser.
Both of these lasers are 532nm green pointers that cost about the same, $196 USD for the Optotronics and $209 USD for the Novalasers. Both Novalasers and Optotronics are regarded as being high quality products, so I thought it would be interesting to compare the lasers against each other.
---------------
We'll start with a comparison of specs.
Optotronics Specs:
IR filter Coatings block >96% of all IR
Laser diode power 1000mW
Average Output Power > 150mW
Laser diode lifetime 5,000 hours MTTF
Beam Diameter (1/e2) <1.5 mm
Beam divergence <1.2 mrad
M2Beam Quality <1.1
Duty cycle @ 21 °C 60/60 sec on/off
Operating temperature 15°C to 30°C
Warranty 90 days
Novalasers Specs:
IR Filter Built-in, 99.5%
Pump Diode 808nm 500mW
Average Output Power > 100mW
Expected Lifetime 3000-5000 hours
Beam Diameter <1.0 mm
Beam Divergence <1.2 mRad
Recommended Duty Cycle 100 sec ON/10 sec OFF
Operating Temperature 15-30 degrees C
Warranty 3 months
These specs are from: Optotronics Green Pen Pointers
and Untitled Page respectively.
The factors that one looks to immediately are average output power, beam diameter, and beam divergence. The Optotronics boasts an output power 50% higher than the Novalasers. But with the smaller beam diameter on the Novalasers, the Novalasers unit actually has an irradiance 50% higher than the Optotronics! This higher irradiance results in a more visible beam as well as better burning power. The divergences of the beams are listed as being the same. Neither company claims their lasers operate in TEM00. More on that later.
Note also that the Novalasers product boasts better IR filtering, and (if it is to be believed, a better duty cycle: I tend to stay well under duty cycles to preserve the integrity of my units.)
Both lasers I received were overspec. The Optotronics laser came with instructions that had "verified 171mW 8/2/2010" written by hand at the top. But it is not clear if this refers to peak or average power. The Novalasers had a printed label stating: "Tested Average Power 115.3mW. Tested Peak: 136mW." The Novalasers product gets points for including both power ratings, not just one unspecified rating. It should be noted that for $30.00 more, one can get a detailed power over time chart from Optotronics detailing a laser's performance. I did not want to pay $30.00 more.
------------
Power.
I do not have a laser power meter to check the power, although I can probably get my hands on one for a test. If I do, I will update this post.
-----------
Irradiance.
Both lasers are very bright at night, with the Novalasers product having a somewhat "greener" beam. This is difficult to capture photographically, and I do not have a picture to illustrate this. I inerpret this "greener" appearance to be due to its higher irradiance. Irradiance is defined to be power per unit area, and thus varies with the distance from the collimation lens of the laser, as the diameter changes with distance. The irradiance decreases with distance (at least past the beam waist).
Since I do not know the actual average power of the Optotronics product, I use the minimum average power of 150mW for calculating the irradiance of the Optotronics laser and the minimum average power of 100mW for the Novalasers laser. (The actual irradiances are naturally somewhat higher.)
Irradiance = Power/Area.
Optotronics laser Irradiance = 150mW/(Pi *(.75mm)^2) = 8.488 W/cm^2.
Actually the above calculation of the Optotronics irradiance is not to be taken to seriously as the beam is not circular, as it does not seem to operate in TEM00.
Novalasers laser Irradiance = 100mw/(Pi*(1mm)^2) = 12.323 W/cm^2.
Thus Novalasers irradiance/Optotronics Irradiance = 1.5. In other words, the irradiance of the Novalasers laser is 50% higher than the Optotronics laser. (EDIT at close range.)
This is dramatically illustrated by the following video in which the lasers fight a book match:
You might wonder if the batteries were a factor in the above test. This was not the case as I measured the batteries immediately after the test:
I notice a lot of people on this forum focus mainly on the output power of their lasers. Since many of the same people are concerned about beam visibility and burning power, they should be more interested in irradiance, not power. Cutting the beam diameter in half increases the irradiance by a factor of 4. Doubling the power only increases the irradiance by a factor of 2. Naturally lenses can be used to focus a beam and obtain a smaller beam diameter, but it is distinctly less impressive to have to put a lens in front of your laser to achieve ignition. Irradiance is the key, not power.
For both of these lasers I am assuming that the lenses in the lasers are collimation lenses and that the beam waist is near the exit point on the front of the lasers. Visual inspection of the beams seems to bear this out. I have been able to light matches with the Novalasers unit from over 10 cm, but I have never been able to light any match with the Optotronics laser at any distance. (I can with a focusing lens, however.)
Remark1: Some inexpensive burning lasers available have lenses that focus the beam near the front of the laser to make dramatic burning easy. This does not seem to be the case with the Novalasers unit. Such lenses usually result in bad divergence a little further away. The Novalasers unit has a spot size at long range that is about the same size as the Optotronics unit.
Remark2: Some inexpensive burning lasers have high IR emissions that aid in burning. If the IR filter specs on the Novalasers unit is correct, it is not burning through its IR emissions.
Burning and beam visibility (irradiance): Advantage Novalasers!
--------------------
Divergence.
I have not yet been able to make a careful measurement of beam divergence for these lasers. This is due to my not having access to a beam profiler, nor had a chance to measure beam diameters past a known far field range. Note, beam diameter measurements made at distances closer than the far field distance are unreliable. In general the far field distance for a laser is given by the formula
Far Field Distance = 100 * d^2/lambda, where d is the diameter of the output aperture and lambda is the wavelength.
For these lasers, I do not know the output apertures, so I don't know the reliable distance for making diameter measurements. Any suggestions on the correct values to use for output apertures for these lasers would be helpful.
Taking the company specs. at face value, one concludes that they have similar divergence behavior.
Advantage: tie.
--------------
Mode behavior.
The Optotronics laser operates consistently in TEM01 (or TEM10, depending on how the laser is rotated.) Here is a picture of the Optotronics beam after 33.3 meters:
I have never seen the Optotronics laser to operate in TEM00. Here is a video of the beam spot at closer range (about 1m with the beam spread through a simple magnification lens):
The Novalasers laser mode hops between TEM00 and TEM01. Here is a shot of the beam at 33.3m operating at TEM00:
Here it is at the same distance operating at TEM01:
Here is a video of the Novalasers unit under operation (with the beam spread through a simple magnification lens) that shows the TEM00 spot:
In general, I have found the behavior of the the Novalasers beam to be quite unpredictable. On some days it seems to stay TEM00, while on others it hops to TEM01 after a few seconds. I have not yet determined the factors which control the mode hopping.
From the above picture, the TEM01 on the Optotronics seems rather muddy; one suspects that several modes are present. The TEM01 on the Novalasers unit seems to be a rather classics double Gaussian image. (The TEM00 on the Novalasers unit also seems to be a rather clear Gaussian image as well.)
Neither company specs their lasers to be TEM00, and Novalasers even states in their printed specs that the beam is multimode. Optotronics makes no mention of mode in their specs.
Mode behavior: Advantage Novalasers!
-----------------
Duty Cycles
Both laser companies give duty cycle information, which is typically missing from lower quality companies. The Novalasers lists a longer duty cycle, with shorter cool-down. Novalasers duty cycle: 100 seconds on / 10 seconds off. Optotronics duty cycle: 60 seconds on/ 60 seconds off.
But I must add that I always stay below duty cycle on-time to avoid damaging my units.
Advantage: Novalasers!
------------------
Host Quality
Aesthetically I like the look of the Novalasers host over the New Wish style host of the Optotronics device. I find the New Wish hosts to have the perennial problem where the internal battery contact spring slips into contact with the outer host and shorts the batteries. This has happened to every laser I have owned with this kind of host, including the Optotronics laser.
I have never had this problem occur with the Novalasers host.
It should also be noted that the Novalasers host has a removable front opening, enabling one to clean the lens, or add accessories. This is not the case with the Optotronics host.
Advantage: Novalasers by a long shot!
--------------
Supplied documentation.
The Optotronics unit came with two little slips of paper giving battery insertion instructions and an over voltage warning. The battery instructions had the power scrawled at the top.
The Novalasers unit came with a zip-lock bag containing four full sheets of paper of instructions and information, including peak power, average power, serial number, legal issues involving laser use, and the specs.
Advantage: Novalasers!
--------------
Packaging and Shipping
Both were well packed, although the Novalasers laser storage box was wrapped loosely in bubble wrap which was contained in another larger box, which also containing the instruction sheets. Also the Novalasers host box is filled with a dense foam which seems to offer more protection than the host box of the Optotronics unit.
The Optotronics unit was contained in its storage box, which was wrapped in bubble wrap, then shipped in a padded envelope.
Both units were shipped quickly, the Novalasers unit in two days and the Optotronics unit in one day.
Advantage shipping: Optotronics
Advantage packaging: Novalasers
----------------------
Subjective feelings.
Quite simply, I am disappointed by the Optotronics laser. I have had the Novalasers unit for about a month now and the Optotronics unit for only about a week, but after experimenting with both, I am decidedly much more impressed with the Novalasers unit. Optotronics gives a power rating, but doesn't state whether it is peak power or average power. For my unit it only says "Verified 171 mW". Is that peak or average? The website doesn't make that clear, although from the example given on the website, one would think it means peak power. This should be made more clear.
Novalasers, while having a small offering on their website, seems specifically targeted to serious hobbyists as well as educators. Both companies have similar prices and warranties for similar products, although Optotronics has many more products available, including serious lab units.
Finally I want to say, that this comparison is based on only one unit from each company, so it is definitely not a large enough sample for a real comparison of companies. It is just my experience with similar units at about the same cost from both companies. The companies seem to have somewhat different markets anyway.
-------------
A question for forum members based on the above review.
Does anyone here know of a company that sells a portable 532nm laser with 100% duty cycle, a collimated beam diameter < 1mm, with power of 150mW or greater? Please don't bother replying with any links that do not meet all three criteria.
I looked over the offerings of companies listed here as being high quality, and didn't see any with such an offering, although I might have missed something.
I may just have to build one myself. It seems that one could start with a diode and lens assembly from one of the Novalasers Alpha HP series and put them into a better host with exceptional cooling to obtain such a portable laser. But I don't know which diodes and lenses are used for these lasers. I also don't know if such a thing is possible with the particular diode used in the Alpha HP lasers; the diode can might heat up too fast for any cooling to make a 100% duty cycle possible. Also, I don't know anything about advanced cooling in hosts.
Any suggestions or thought would be welcome. Thanks!
-------------
About me.
I am a educator and professional technical person in a different field from laser technology, although I have had training as a laser technician in the past. I consider myself a laser hobbyist and have been using lasers since high school (then college physics lab units), but have only recently purchased some of the nice diode/DPSS units that have lately become readily available. I look forward to building and experimenting with many more lasers in the future. This is my first post on any laser hobbyist forum.
Last edited:
this is wonderful option....
