I received a very good question from a reader about my article last week. The question was about interference between these radar systems on a crowded highway. I couldn’t easily find a good answer about this online, but my suspicion about this is that these systems function in a way similar to consumer-grade wifi transmitters. A full apartment complex might have a dozen or more wifi transmitters on top of each other spitting out signals that overlap and potentially interfere. This situation would be similar to lots of cars packed together on a highway. Wifi transmitters are designed with this possibility in mind. They use different transmission “channels”, basically just different frequency groups, to keep their own traffic under control and optimized. A transmitter will do this automatically by design. I’m almost positive radar systems in cars work the same way. Since they are radio frequency-based, they too can operate on discrete channels and switch to new channels if one has too much interference. However, one thing I did see a lot about was that these radar systems do mess with consumer-grade radar detectors pretty badly. So much so that detector manufacturers are starting to have to design their devices more intelligently.

Onto my topic for this week: lasers! Believe it or not, when the first lasers were invented in the 1960s, scientists called them “a solution in search of a problem.” It wasn’t apparent at that time how much use lasers could be, but today we rely on them from things as simple as barcode scanning at the grocery store to the fibre connections that form the backbone of the entire internet. Lasers are pretty complex pieces of technology and they involve some electrochemistry too (not my strong suit) but I’ll do my best to explain them for you here.

First of all, the word laser, like radar, is an acronym that stands for “light amplification by stimulated emission of radiation.” Would you like fries with that? The acronym is descriptive, but is complicated. At the heart, a laser has some kind of gain medium which can be energized somehow as well as some kind of construction that can provide optical feedback. The amplification part comes in when we start with the gain medium. In order for it to amplify light, we need to give it something to start with. Either energy (in the form of electricity) or light from some other source. This process of supplying energy to the gain medium is called pumping. Lasers can be pumped with many things including flash lamps, electricity or another laser.

A simple laser could be described as the following. Imagine a cylinder composed of the material to be pumped. On each end of the cylinder is a mirror facing the cylinder. When the gain medium material is pumped, it gives off photons in an amplified state which bounce back and forth between the mirrors, passing through the gain medium and being amplified more each time. Now imagine if one of the mirrors was translucent allowing some light to escape. We’d have a laser!

What is the gain medium composed of? In most industrial or scientific lasers, the gain medium is often some kind of gas, like helium, helium-neon, or carbon dioxide. If the gain medium is a solid, we call these solid state lasers. In these lasers, the gain medium consists of a glass or crystalline rod that is “doped” with ions in a process similar to “doping” silicon for use in photovoltaics. Finally there are semiconductor lasers. These lasers, while technically solid state, are not generally referred to as such and are most common in consumer grade devices. They are composed of diodes that are electrically pumped and function most similarly to our basic example above.

As they are most common in our daily lives, I’ll explain a bit more about semiconductor lasers. They can be made to emit laser radiation at wavelengths from 375nm to 3500nm. Why are so many of these lasers red though? Most laser pointers are red for example, as are most barcode scanners. The reason is because laser diodes are cheaply available in those wavelengths. To achieve shorter wavelengths, more sophisticated techniques need to be used. I have a green laser pointer at home that I got in 2006 for about $75 online. Little did I know at the time, but green lasers such as that one only became widely available to consumers in the early 2000s. Green semiconductor lasers are most often a type of diode-pumped, solid-state, frequency-doubled laser. The green light is generated via a two step process that starts with a lower energy laser diode in the infrared spectrum. This light is used to pump a—brace yourself—-yttrium orthovanadate crystal doped with neodymium. That gain medium is then where the green laser light comes from. I think laser scientists just want to obfuscate their devices with wild names.

I have to stop there because even my head is spinning a bit. Hopefully this was an ok explanation of these interesting and useful devices.

Grace and I are preparing for our summer motorcycle ride. This year we are going to ride down the Blue Ridge Parkway to view the total eclipse of the sun and to visit our friend Jen Mayer at Charlotte Street Computers in Asheville. We’ve got our special eclipse viewing glasses and we are almost all ready.

We are riding down tomorrow to Rutland to get Grace some new tires for her Victory Vision and then we are ready. I rigged up a cup holder that holds my 30 ounce Yeti so cold brew will be the drink for the trip.

Great year for blueberries, btw.

Thank you for reading this issue of Kibbles & Bytes!

Your Kibbles & Bytes Team,

Don, Emily & Hadley

I am by no means an artist nor someone who has drawn anything beyond your standard High School art class. However something drew my attention the Apple Pencil, call it intrigue or even memorization of the new slick addition to the Apple line up I could not keep from considering why it was so endearing. Whatever the calling was I finally made up my mind and purchased one of these compelling little stylus, and boy oh boy was I impressed. I had little experience playing with the abilities of the Apple Pencil outside of the store. I have discovered a new found obsession with sketching.

For anyone who has ever drawn with your standard paper and pencil, (as well if you are as nit picky as I am) you will quickly find by erasing multiple strokes several times you quickly create this indent on the paper, an indent that will never go away. This is infuriating! As with any drawing tablet this frustration is elevated when using a computer to render your work allowing easy (Command – Z) undo functionality. There are some intense differences when comparing drawing tablets vs paper and pencil, and many artists strongly dislike the separation between the two. Again, I am no artist and do not claim to have a strong history with any of the options discussed. However I must express my complete and wonderful surprise that was using the Apple Pencil. The fluidity, precision and pencil likeness was unmatched by any expectations I had. Whether it be lightly sketching out the initial point of reference lines or deeply highlighting the final details it feels as though I am sketching on a piece of paper just underneath the glass of my iPad Pro.

Without spending all day going into details and further examples, I’ll wrap this up with a final thought. The Apple Pencil is not just for Artists, or people in the field of artistry. If you are someone who draws, sketches, paints or even prefers written notes, the Apple Pencil can be another tool added to the arsenal. Even if you are like me, someone who has never tackled anything artistic but has a nagging urge to create, I highly encourage swinging down to Small Dog and testing out the Apple Pencil. We have one at the counter anyone can test out on one of our iPad demo models and see for yourself what makes it such a unique and diverse product.