In hair removal procedures, most long-pulsed Nd:YAG and Alexandrites lasers typically use short pulsewidths – usually less than 10ms, often less than 5ms. They can deliver all of their energy within these short pulses, whereas diode lasers and IPLs typically use longer pulses. Such short pulses induce higher temperatures in the absorbing targets in the skin,… Continue reading Why are Nd:YAG and Alexandrite lasers ‘easier’ to use in hair removal?
Category: Interesting stuff
Colour-changing tattoos and how annoying they are…
In my laser tattoo removal training course I discuss a case which happened to me many years ago (about 32, or so). A partially red tattoo was treated by our QS ruby laser using the standard parameters of the day (about 6 J/cm^2 in a 25ns pulse). When the patient returned for his second session,… Continue reading Colour-changing tattoos and how annoying they are…
What exactly is “calibration” and why is it so important in laser/IPL treatments?
What is ‘calibration’ exactly and why is it so important? Imagine you’re driving along the road and your speedometer is not working properly. You look at it and it claims you’re moving along at 30 mph. But you notice that everyone else is driving past you and you seem to be going too slowly… This… Continue reading What exactly is “calibration” and why is it so important in laser/IPL treatments?
I’ve known for a long time that black and white are not ‘colours’. But I didn’t know that purple is also not a colour…
In physics we define ‘colour’ by its wavelength. But there are colours which do not have a wavelength – black and white are the obvious ones. Black is when there is no light at all, and white is when all the colours in the spectrum ‘combine’ together into one beam of light. But, I recently… Continue reading I’ve known for a long time that black and white are not ‘colours’. But I didn’t know that purple is also not a colour…
Laser Diode powers – What does it all mean?
Diode laser suppliers often quote ‘power’ when trying to sell their equipment. They know, of course, that most people don’t have a clue about what they actually mean!! I wrote about this before (link) but here I go again… Power Power is essentially how quickly, or how slowly, energy is delivered. Remember, ENERGY is the… Continue reading Laser Diode powers – What does it all mean?
My blog posts in an online book format
I’ve put many of my posts together into an online pdf. This makes easier find some of my articles various topics… https://online.flipbuilder.com/rbhw/zeal/mobile/index.html Enjoy, Mike.
I checked my eyes. This is what I found…
My opticians called to ask me in for an assessment. They know I work with lasers so they thought it might be wise… Lo and behold, she found a spot of damage in the lower left of my left eye – you can see the lighter patch near on the edge of my retina, above.… Continue reading I checked my eyes. This is what I found…
More on “Manufacturers’ Settings” and how bad they are…
Yesterday, I visited a very nice lady to train on the use her very expensive laser. She’d had previous training on laser hair removal but was not obtaining good results. Most of her clients were returning with thinner, finer hairs – yet, she was following the ‘manufacturers’ guidelines’ religiously. What was going wrong? Her machine… Continue reading More on “Manufacturers’ Settings” and how bad they are…
When is a laser beam not a laser beam? When it enters the skin…
Laser light is unique due to three particular properties: Monochromacity Divergence Coherence Lasers generate a very narrow band of wavelengths, typically within a few nanometres around a central line. So, a ruby wavelength of 694nm will actually be a spread between 692 and 696nm, depending on how ‘good’ the resonator is. Poor resonators will have… Continue reading When is a laser beam not a laser beam? When it enters the skin…
Time travel… Is it possible?
As some of you know, my background is in physics and astronomy. (Don’t tell me your ‘star sign’ as a smack in the mouth often hurts…!!!) I apply my physics training to lasers and IPLs and stuff, but I don’t really use my astronomy education much, these days. I like to ‘keep up’ by reading… Continue reading Time travel… Is it possible?
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