In this episode, Mike and Lisa delve into the fascinating world of physics as it relates to lasers and skin treatments. They break down complex concepts such as absorption, scattering, and anisotropy in a way that's easy to understand, even for a five-year-old. Through engaging examples, they explain how photons interact with atoms, leading to either absorption or scattering, and how this affects the effectiveness of different wavelengths in laser treatments.

KEY TAKEAWAYS

• When photons encounter atoms, they can either be absorbed or scattered. Absorption occurs when the energy of a photon matches the energy required for an electron to jump to a higher orbital, while scattering happens when the photon does not match this energy and is redirected.

• Absorbed photons increase the energy of the atom, leading to a higher vibrational state, which is perceived as heat. In contrast, scattered photons do not contribute to heating the atom but can create new photons of the same energy.

• Different wavelengths of light have varying absorption coefficients for different materials. For example, green ink absorbs red light well but poorly absorbs green light, making it ineffective to use green light on green ink in tattoo removal.

• Scattering is influenced by anisotropy, which refers to the directionality of scattered photons. High anisotropy means photons tend to scatter in the same direction as the incoming light, while low anisotropy results in more random scattering, affecting how deeply light penetrates the skin.

• The effectiveness of laser treatments, such as hair removal, is influenced by the wavelength used and the fluence (energy per unit area). Lower wavelengths tend to be more aggressive and can cause more damage to the upper layers of the skin due to their strong absorption in melanin and limited penetration depth.

BEST MOMENTS

"If the energy of the photon matches one of those transitions, then that atom can absorb that photon."

"When light enters your eyeball and it hits the retina, somehow you perceive colour."

"You could have something which strongly absorbs red lights, but doesn't like blue light."

"Absorption is the warm atom and a new photon is scattering."

"Blue light will generate much more damage in the epidermis compared to, say, red light."

ABOUT THE HOSTS

Mike began his career in medical lasers in 1986 with a physics degree and a post-grad in bioengineering. He helped develop the scar-free removal of tattoos using a Q-Switched Ruby Laser in Glasgow, and the world's first IPL system. Known well in the industry for his hard truths, no BS attitude and logical answers. As the author of three books, articles for medical journals, a well read blog, a Laser Protection Advisor and contributor to the BMLA, Mike is the Laser Guru.

Lisa's claim to laser fame is being Mike's daughter. Growing up with lasers and never avoiding a physics lesson from her Dad, it was natural to enter the industry. Leaving a corporate career with a baby to jump into self employed life came with challenges. Despite that Lisa has been well recognised for her teaching style, practical tips, bringing the compassion to the science, and laser mentoring.

Instagram: @dermalase_lasertraining

https://mikemurphyblog.com

https://www.dermalasetraining.com

This Podcast has been brought to you by Disruptive Media. https://disruptivemedia.co.uk/