Jarrod Kinsey: My First Successful Organic Dye Lasers

My Projects: Organic Dyes Pumped by Nitrogen Lasers

First Successful Results

WARNING: Construction and operation of any laser device is hazardous. Do not attempt to construct or operate a laser without adequate safeguards and safety practices. Most lasers involve high voltages, toxic chemicals, high vacuum, laser radiation and other hazards. The author specifically disclaims any and all liabilities associated with the construction and use of such devices. Designs presented here are in the interests of providing information on operational principles only and do not represent safe nor ANSI safety compliant designs.

Here is a photo of Rhodamine 6G in 91% isopropyl alcohol, in a homemade cuvette, pumped by a homemade TEA nitrogen laser. It marks the first time I have been able to use one of my nitrogen lasers to lase an organic dye —

The cuvette is made of four microscope coverslips, epoxied together and epoxied onto a microscope slide.

It is extremely important to have the correct concentration of dye in the solution, and it really helps to have a cylindrical lens to focus the beam from the nitrogen laser into a line on the front face of the cuvette. If you do not have a cylindrical lens, you will need either external mirrors or an extremely powerful nitrogen laser.

Here is 4-Methyl-Umbelliferone, also in 91% isopropyl alcohol, but with a few drops of ammonia added (4-MU requires an alkaline environment) —

Here is Rhodamine 6G being lased by one of my TEA nitrogen lasers, but with air in the channel rather than nitrogen. You can see that the spot on the target is not very bright. That’s because this is hard to do!

One important thing that is not visible in the photo above is the fact that this is not an LC-Inversion circuit laser. It is a Charge-Transfer circuit. Here is an overview:

(The CD disk is for scale, so you can see how large the parts of the laser are.)

Notice that the positions of the spark gap and the laser channel are swapped in this design, and that the main storage capacitor is considerably larger than the “peaker” capacitor. (The peaker is just the right side of the laser; the rod on the left is connected to the ground plane.)

Nitrogen vs Air

Here are some photos showing the difference in output. Each picture shows four or five pulses from the TEA nitrogen laser hitting a cuvette of 4-Methyl-Umbelliferone. The output of the dye is shown on paper and on cork. The upper two photos were taken with air in the laser, and the lower two are with nitrogen. As you can see, nitrogen works a lot better!


Jon Singer provided me with the proceeding HTML and text. The web pages at jarrodkinsey.com were provided by Jon as well. After I learned some basic HTML and purchased my own domain, I began to build jarrodkinsey.org.

The dye lasers were a product of my early laser work. They were made possible by instruction and guidance I received from Mr. Jon Singer. As a researcher with some background in chemistry and physics, Mr. Singer had unusual insight into the nature of organic dyes. He was able to tell me which chemicals could be made to lase, and under what conditions.

Mr. Singer brings his knowledge of chemistry to the table of quantum physics: a beneficial combination with substantial advantages over solely physics based research.

Laser Using Laundry Detergent

Laundry detergent is a cheap source of laser dye. Arm and Hammer concentrated laundry detergent, will work straight out of the bottle. However, if you want to try it, you need to make sure that the product description states that there are no perfumes or dyes present. When stating this, the manufacturer is obviously talking about a different kind of dye. We are interested in the optical brightener that is contained in this detergent. The optical brightener is responsible for absorbing UV light from the sun and other sources, and emitting visible blue light. This causes clothes to have a brighter than normal appearance. Without the brightener, a white T shirt would have a yellow hue to it, and would not appear to be as clean as a T shirt treated with optical brightener. See details below, and click on any picture for a larger view.

Here is the product I am referring to:

Here is some laundry detergent in action:

Laundry detergent is easy to lase, and it results in a lovely shade of blue or violet-blue; an interesting color in a world that is already familiar with red and green laser sources. If you can manage to focus your nitrogen laser pump beam tightly enough, with a cylinderical lens, then you might be able to get a relatively well colimated beam from the detergent, without any additional optics. Take a look at this picture, to see what I mean.

The basic setup is quite simple. Here is a basic example of a nitrogen laser pumped dye, with the individual parts labeled.

If you pump laundry detergent using a small laser like this, you will not get much power. Using pure nitrogen, however, will work wonders for any sized TEA laser, but with the one shown above, it is still possible to get weak lasing with an open channel and air, as shown below.

October, 2017

On the left are a couple of pictures showing lasing of All Free and Clear brand laundry detergent. Arm and Hammer brand undoubtedly works better, but All Free and Clear is the brand I use for my actual laundry, and it's thus the only brand I currently have at my disposal.

The output appears to be closer to violet than blue, and it is very difficult to see at such low average power. Given that the detergent doesn't make the best dye, air is being used instead of nitrogen and the cuvette is made of plastic, the laser output is difficult to see or photograph, and it's hard to appreciate in a world where laser sources are familiar, relatively common and taken for granted.

I discovered a fluorescent target to be the best option for visualizing this violet output - although the output from the dye is a visible wavelength, it's too far from the peak sensitivity of human vision to be clearly visible at such low average power.

If attempting to lase laundry detergent with an air laser, I recommend using a fluorescent target. Best results can be obtained using a fluorescent target with a really bright color, such as yellow. In the absence of such a target, the dye output will be very difficult to see. In the photos where the target was not used, the spot from the dye appears as a dull purple spot. If I remember correctly I used a 30s shutter speed to make the following three photos, so they represent several superimposed pulses. To the eye, they are therefore considerably fainter than they appear in these photographs.

In the 3 photographs to the left, the dye output can be seen on targets that are not fluorescent. This is the actual laser light, and the difference in brightness is quite evident.

In this short video clip, the 'air' laser-pumped detergent laser is shown in action, with a fluorescent target to indicate the detergent laser output.

Contact Information

You can reach me at an email address that you construct from the following three gmail pieces: com, along with jarrod694. (I don’t offhand know whether that’s enough to prevent robots from harvesting the@address.and making spam from it, but I certainly hope so.)

Last modified: Sun Mar 25 01:11:08 EDT 2007