April 14, 2025 • 12 mins
Episode Description:
Think spot size is just about how big your laser beam is? Think again. In this Fast Science episode of Laser Secrets, Jamie breaks down everything you need to know about spot size — in under 15 minutes.
You’ll learn:
• What spot size actually does
• How it affects penetration depth and fluence
• The inverted triangle analogy (that makes it all finally make sense!)
• How to pair spot size with the right wavelength
• When to go small vs. when to go big for real results
Whether you’re treating hair, vessels, pigment, or tattoos, this episode gives you the clarity you need to dial in your settings like a pro.
Perfect for new techs, experienced providers, and anyone who wants faster, safer, and more effective laser results.
Stay Connected & Explore:
-
All Links & Resources: https://linktr.ee/lasersecrets
-
Follow Jamie on Instagram: https://www.instagram.com/laser_secrets_consulting
-
Find Esthetician-Approved Products Jamie Recommends:
https://app.pompbeauty.com/pomp-pro/amFtaWVhbnl0aW1lZml0QHlhaG9vLmNvbTpjdXN0b21lcjoxNzE4MDMxMTcwNTY2 -
Email for Show-Related Inquiries and Sponsorships: lasersecrets@yahoo.com
Credits:
Podcast production by Brand|Sound. Start your podcast journey by emailing brandsoundpodcasts@gmail.com.
Chapters:
00:00 Introduction to Laser Secrets
01:17 Understanding Spot Size
01:36 Depth of Penetration and Fluence
02:05 Inverted Triangle Analogy
03:12 Practical Applications of Spot Siz
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:00):
Hello, my laser loving friends.
Welcome to Laser Secrets, thepodcast that's all about giving
you the knowledge, confidence, andthe skills you need to be the best
aesthetic laser practitioner possible.
I'm your host, Jamie.
I'm a laser-obsessed med spaowner, medical aesthetician, laser
specialist, and passionate educatorin the world of medical aesthetics.
(00:23):
Today's episode is part of my fastscience series where we take laser
concepts and make them simple,actionable, and easy to understand.
Today we're diving into spot size,what it actually does, why it matters
in every treatment, and how to getused to using it to get better results
without overtreating and underwhelming.
(00:46):
In this episode, I'll give you a quickunderstanding of how spot size affects
laser behavior, how it interacts withdepth, fluence, and penetration, when
to use smaller versus larger spot sizes,and the inverted triangle analogy that
I hope will really help you to visualizethis and put it all together so you can
(01:07):
start using it and understanding how touse your laser more efficiently today.
Okay, let's get to it.
Spot size is the diameter of thelaser beam at the surface of the skin.
It's measured in millimeters, you'llsee options like two millimeter,
six millimeter, 10, and so on.
(01:30):
all depending on your device.
So it influences three major things.
So first of all is depth of penetration.
Next is fluence, which isenergy per centimeter square.
Third is treatment coverage, and speed.
And it's not just about how much areayou can cover, it directly impacts how
(01:55):
effective and safe the treatment can be.
So let's get to the visual.
I really love this and thisreally helped it sink in for me.
It's the inverted triangle analogy.
So picture an inverted triangle atits base, it's on the surface of the
skin, so it narrows as it goes deeper.
(02:19):
Laser energy follows that path.
It enters wide and narrows as ittravels deeper into the tissue.
But here's the catch.
As energy travels down throughthe triangle and into the
skin, it actually loses power.
This is called attenuation.
Some of it is absorbed.
(02:39):
Some of this energy actuallyback scatters and some dissipates
as it moves through tissue.
a smaller spot size starts with asmaller, more narrow triangle base,
which means the energy doesn't reachvery far, it stays superficial.
A larger spot size starts with a widertriangle base, so the energy can travel
(03:00):
a little bit deeper into the skinbefore it essentially loses steam.
This is why larger spot sizesare great for deeper penetration.
Smaller spot sizes are more superficial.
So let's, connect this to fluenceand how much energy is being
delivered per unit of area.
the basics are fluence is Joulesdivided by centimeters squared.
(03:25):
So it's energy divided by area.
If you increase the spot size,you increase the area, so
the fluence actually drops.
If you decrease the spot size, thearea shrinks so the fluence, goes up,
which means if you have a spot sizeof 20 and you are using a fluence
(03:49):
of, say, 20 joules, that is goingto be spread over a larger area.
And think of that inverted triangle.
It's going to be.
A larger area, but that meansalso the energy is dissipating
because you're still using.
20 joules.
If you go to a five millimeterspot size and you're still using
(04:11):
20 joules, that is a heavilyconcentrated area of energy being used.
So, you know, really when we'rethinking about what treatment, you
must keep that in consideration andyou really must recheck flus, some.
Devices auto adjust.
I'm not a huge fan of that.
I'm a fan of us knowing our laser physicsand as long as our devices are calibrated
(04:36):
properly, we should be able to go up toany device and understand how to use it.
So I'm really big on, everyoneto understand truly like the
real physics behind this.
okay.
So let's then.
Match spot size to wavelength.
With some really common treatment goals.
(04:57):
And I'm sure, you know, if you're alaser technician already, this isn't
going to be anything foreign to you.
but just to kind of think about like,okay, when we want that energy to be more
concentrated and shallow, how that spotsize really matters versus dissipating
it a little more with a larger spot size.
for superficial treatments likepigmentation, small vessels like
(05:19):
Telangiectasia, you know, whetheryou're using a long pulse, 532
or a long pulse, 1064 ND/YAG.
we typically use the smaller spot sizes.
for my quanta Evo Light star,I love to use between a two and
a five millimeter spot size.
Depending on which vessel I'm treating,going into our Alexandrite 755 nanometers.
(05:45):
this is a little more mid death.
we use this a lot for our hair removaltreatments and, spot sizes of like
10 to 18 can be really great for.
Our hair removal.
and it's because, you know, as you dropthose spot sizes too, you can, you can go
a little higher with, the fluence as faras like what your device will let you do.
But again, always triplecheck those settings.
(06:08):
I've said this before in a previousepisode, but you cannot unring a bell.
You can never, have too many safetychecks when it comes to, prepping
your client, making sure you know theyhaven't been on antibiotics or changed
to photo sensitizing medications.
And triple.
Check those settings, before you fire.
(06:29):
next, I'm getting offmy little rant there.
with, you know, if you're using the 1064ND/YAG again for hair removal, this is
great for our, darker skinned clients,also targeting those deeper follicles.
But typically we'll see, you know, thespot size of like 12 and up for that.
(06:50):
So wavelength gives you potential depth,spot size helps you get there efficiently.
So when we're, Really thinking aboutthis again, let's really, really
lock in some of these fundamentals.
Larger spot size equalsdeeper penetration.
you still get that backscatter, it dissipates.
(07:12):
Smaller spot size is moresuperficial, but you can really
have a more intense treatment area.
Again, that fluence, youcan have a 20 Joule fluence.
you know, Joules by centimeter squared.
In a large spot size and use the same20 joules in a smaller spot size,
that smaller spot size is going tobe a much more intense treatment.
(07:35):
one little side note too I want tomention is when you're doing tattoo
removal, now this is done only with ourQ switch or Pico laser technologies.
the reason why I say that is becauseI'm still seeing some places using
the wrong type of laser For tattooink, and this is a big no-no.
(07:56):
if you're someone who's been inthe industry, you're probably
like, oh seriously, no doubt.
Do you really have to say it.
But unfortunately we do.
I see it even in our own area.
And what happens is if you're usingthe wrong kind of laser or you're using
like a photothermal or long pulse laser.
It's like hitting that inkwith a lightning strike.
You know, you're gonna basically boilthat ink to the surface and, that
(08:21):
creates a pretty significant wound.
That wound will scab, scab falls off,there's a scar left, and we just do
not want that for our client's skin.
So when you use something like aQ switch or pico, it's more of a
photoacoustic type of mechanism.
So think of like that earthquake ofenergy versus that lightning strike.
(08:42):
So that inertia of the energyis going down into the skin
and breaking apart that ink.
so really when you're doing tattooremoval with a Q switcher, pico, those
early sessions, a larger spot size,is actually recommended because you
are dissipating that fluence a littlemore and you're shattering that surface
(09:04):
pigment as you get deeper into the tattoo.
I really love to adjust down my spotsize because then I can go a little
higher in fluence and I can reach thosedeeper particles that are stubborn.
And, you know, tattoo removal is oneof the few times where you shrink the
spot size and increase the fluence.
this is because, as the ink fades youwanna get deeper and that requires
(09:28):
a higher fluence for tattoo removal.
I will do some episodes coming uphere on laser tattoo removal and even
permanent makeup removal because.
That is one of my favorite, likeabsolute favorite treatments to
do, and I love to talk about it.
So just to recap, larger spot size equalsdeeper penetration, smaller spot size,
(09:51):
more superficial, but more intense.
Think about those inverted triangles.
always, always, always recheckthat fluence when you're changing
spot size and even before you fire.
Even if you're like, okay, I've donethese treatments a thousand times,
always please triple check thosesettings because we cannot unring a
bell and, we want the best for allof our clients and great results.
(10:15):
Safety is first and foremost.
So when you really understand how touse spot size with your wavelength, you
get smarter, safer, and more predictableoutcomes, which is what we all want.
really, I highly recommend don'tlet your machine auto pick.
if you have a machine that is justlike "Hair Removal: Fitz-3", you know,
(10:37):
still really, really think about this.
And even if your machine is an autopick type of thing, if you can set it
in manual, I really recommend that.
But once you truly understand like how,changing one thing affects another,
really what I want for you is toreally be able to go up to any of your
devices, and like I said, as long asthey're calibrated properly, you will
(11:00):
know how to use them, how to get thebetter results, how to troubleshoot.
Also, because sometimes we haveclients that come in and, sometimes
the tissue we're affecting just isn'tresponding the way, textbook- wise
would tell us, so that way youcan really know your equipment.
Okay.
(11:21):
My laser loving friends, thiswas a quick one today, but I
really wanted to chat about that.
this wraps up today'sfast science episode.
I hope this discussion onspot size has been useful.
If you enjoyed this episode, pleasesubscribe, leave a review, and share
it with your fellow aesthetic pros.
(11:42):
And if you have any questions,suggestions, or interested in working
with me directly, I do consulting.
send me a DM At @Laser_Secrets_Consulting,you can follow the links
in the bio of the show.
until next time, stay confident,stay curious, and here's to having
the best laser results ever.
Hello, my laser loving friends.
Welcome to Laser Secrets, thepodcast that's all about giving
you the knowledge, confidence, andthe skills you need to be the best
aesthetic laser practitioner possible.
I'm your host, Jamie.
I'm a laser-obsessed med spaowner, medical aesthetician, laser
specialist, and passionate educatorin the world of medical aesthetics.
(00:23):
Today's episode is part of my fastscience series where we take laser
concepts and make them simple,actionable, and easy to understand.
Today we're diving into spot size,what it actually does, why it matters
in every treatment, and how to getused to using it to get better results
without overtreating and underwhelming.
(00:46):
In this episode, I'll give you a quickunderstanding of how spot size affects
laser behavior, how it interacts withdepth, fluence, and penetration, when
to use smaller versus larger spot sizes,and the inverted triangle analogy that
I hope will really help you to visualizethis and put it all together so you can
(01:07):
start using it and understanding how touse your laser more efficiently today.
Okay, let's get to it.
Spot size is the diameter of thelaser beam at the surface of the skin.
It's measured in millimeters, you'llsee options like two millimeter,
six millimeter, 10, and so on.
(01:30):
all depending on your device.
So it influences three major things.
So first of all is depth of penetration.
Next is fluence, which isenergy per centimeter square.
Third is treatment coverage, and speed.
And it's not just about how much areayou can cover, it directly impacts how
(01:55):
effective and safe the treatment can be.
So let's get to the visual.
I really love this and thisreally helped it sink in for me.
It's the inverted triangle analogy.
So picture an inverted triangle atits base, it's on the surface of the
skin, so it narrows as it goes deeper.
(02:19):
Laser energy follows that path.
It enters wide and narrows as ittravels deeper into the tissue.
But here's the catch.
As energy travels down throughthe triangle and into the
skin, it actually loses power.
This is called attenuation.
Some of it is absorbed.
(02:39):
Some of this energy actuallyback scatters and some dissipates
as it moves through tissue.
a smaller spot size starts with asmaller, more narrow triangle base,
which means the energy doesn't reachvery far, it stays superficial.
A larger spot size starts with a widertriangle base, so the energy can travel
(03:00):
a little bit deeper into the skinbefore it essentially loses steam.
This is why larger spot sizesare great for deeper penetration.
Smaller spot sizes are more superficial.
So let's, connect this to fluenceand how much energy is being
delivered per unit of area.
the basics are fluence is Joulesdivided by centimeters squared.
(03:25):
So it's energy divided by area.
If you increase the spot size,you increase the area, so
the fluence actually drops.
If you decrease the spot size, thearea shrinks so the fluence, goes up,
which means if you have a spot sizeof 20 and you are using a fluence
(03:49):
of, say, 20 joules, that is goingto be spread over a larger area.
And think of that inverted triangle.
It's going to be.
A larger area, but that meansalso the energy is dissipating
because you're still using.
20 joules.
If you go to a five millimeterspot size and you're still using
(04:11):
20 joules, that is a heavilyconcentrated area of energy being used.
So, you know, really when we'rethinking about what treatment, you
must keep that in consideration andyou really must recheck flus, some.
Devices auto adjust.
I'm not a huge fan of that.
I'm a fan of us knowing our laser physicsand as long as our devices are calibrated
(04:36):
properly, we should be able to go up toany device and understand how to use it.
So I'm really big on, everyoneto understand truly like the
real physics behind this.
okay.
So let's then.
Match spot size to wavelength.
With some really common treatment goals.
(04:57):
And I'm sure, you know, if you're alaser technician already, this isn't
going to be anything foreign to you.
but just to kind of think about like,okay, when we want that energy to be more
concentrated and shallow, how that spotsize really matters versus dissipating
it a little more with a larger spot size.
for superficial treatments likepigmentation, small vessels like
(05:19):
Telangiectasia, you know, whetheryou're using a long pulse, 532
or a long pulse, 1064 ND/YAG.
we typically use the smaller spot sizes.
for my quanta Evo Light star,I love to use between a two and
a five millimeter spot size.
Depending on which vessel I'm treating,going into our Alexandrite 755 nanometers.
(05:45):
this is a little more mid death.
we use this a lot for our hair removaltreatments and, spot sizes of like
10 to 18 can be really great for.
Our hair removal.
and it's because, you know, as you dropthose spot sizes too, you can, you can go
a little higher with, the fluence as faras like what your device will let you do.
But again, always triplecheck those settings.
(06:08):
I've said this before in a previousepisode, but you cannot unring a bell.
You can never, have too many safetychecks when it comes to, prepping
your client, making sure you know theyhaven't been on antibiotics or changed
to photo sensitizing medications.
And triple.
Check those settings, before you fire.
(06:29):
next, I'm getting offmy little rant there.
with, you know, if you're using the 1064ND/YAG again for hair removal, this is
great for our, darker skinned clients,also targeting those deeper follicles.
But typically we'll see, you know, thespot size of like 12 and up for that.
(06:50):
So wavelength gives you potential depth,spot size helps you get there efficiently.
So when we're, Really thinking aboutthis again, let's really, really
lock in some of these fundamentals.
Larger spot size equalsdeeper penetration.
you still get that backscatter, it dissipates.
(07:12):
Smaller spot size is moresuperficial, but you can really
have a more intense treatment area.
Again, that fluence, youcan have a 20 Joule fluence.
you know, Joules by centimeter squared.
In a large spot size and use the same20 joules in a smaller spot size,
that smaller spot size is going tobe a much more intense treatment.
(07:35):
one little side note too I want tomention is when you're doing tattoo
removal, now this is done only with ourQ switch or Pico laser technologies.
the reason why I say that is becauseI'm still seeing some places using
the wrong type of laser For tattooink, and this is a big no-no.
(07:56):
if you're someone who's been inthe industry, you're probably
like, oh seriously, no doubt.
Do you really have to say it.
But unfortunately we do.
I see it even in our own area.
And what happens is if you're usingthe wrong kind of laser or you're using
like a photothermal or long pulse laser.
It's like hitting that inkwith a lightning strike.
You know, you're gonna basically boilthat ink to the surface and, that
(08:21):
creates a pretty significant wound.
That wound will scab, scab falls off,there's a scar left, and we just do
not want that for our client's skin.
So when you use something like aQ switch or pico, it's more of a
photoacoustic type of mechanism.
So think of like that earthquake ofenergy versus that lightning strike.
(08:42):
So that inertia of the energyis going down into the skin
and breaking apart that ink.
so really when you're doing tattooremoval with a Q switcher, pico, those
early sessions, a larger spot size,is actually recommended because you
are dissipating that fluence a littlemore and you're shattering that surface
(09:04):
pigment as you get deeper into the tattoo.
I really love to adjust down my spotsize because then I can go a little
higher in fluence and I can reach thosedeeper particles that are stubborn.
And, you know, tattoo removal is oneof the few times where you shrink the
spot size and increase the fluence.
this is because, as the ink fades youwanna get deeper and that requires
(09:28):
a higher fluence for tattoo removal.
I will do some episodes coming uphere on laser tattoo removal and even
permanent makeup removal because.
That is one of my favorite, likeabsolute favorite treatments to
do, and I love to talk about it.
So just to recap, larger spot size equalsdeeper penetration, smaller spot size,
(09:51):
more superficial, but more intense.
Think about those inverted triangles.
always, always, always recheckthat fluence when you're changing
spot size and even before you fire.
Even if you're like, okay, I've donethese treatments a thousand times,
always please triple check thosesettings because we cannot unring a
bell and, we want the best for allof our clients and great results.
(10:15):
Safety is first and foremost.
So when you really understand how touse spot size with your wavelength, you
get smarter, safer, and more predictableoutcomes, which is what we all want.
really, I highly recommend don'tlet your machine auto pick.
if you have a machine that is justlike "Hair Removal: Fitz-3", you know,
(10:37):
still really, really think about this.
And even if your machine is an autopick type of thing, if you can set it
in manual, I really recommend that.
But once you truly understand like how,changing one thing affects another,
really what I want for you is toreally be able to go up to any of your
devices, and like I said, as long asthey're calibrated properly, you will
(11:00):
know how to use them, how to get thebetter results, how to troubleshoot.
Also, because sometimes we haveclients that come in and, sometimes
the tissue we're affecting just isn'tresponding the way, textbook- wise
would tell us, so that way youcan really know your equipment.
Okay.
(11:21):
My laser loving friends, thiswas a quick one today, but I
really wanted to chat about that.
this wraps up today'sfast science episode.
I hope this discussion onspot size has been useful.
If you enjoyed this episode, pleasesubscribe, leave a review, and share
it with your fellow aesthetic pros.
(11:42):
And if you have any questions,suggestions, or interested in working
with me directly, I do consulting.
send me a DM At @Laser_Secrets_Consulting,you can follow the links
in the bio of the show.
until next time, stay confident,stay curious, and here's to having
the best laser results ever.
Popular Podcasts
Cold Case Files: Miami
Joyce Sapp, 76; Bryan Herrera, 16; and Laurance Webb, 32—three Miami residents whose lives were stolen in brutal, unsolved homicides. Cold Case Files: Miami follows award‑winning radio host and City of Miami Police reserve officer Enrique Santos as he partners with the department’s Cold Case Homicide Unit, determined family members, and the advocates who spend their lives fighting for justice for the victims who can no longer fight for themselves.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.