A long pulse Nd:YAG laser and a Q-switched Nd:YAG laser share the same 1064 nm wavelength, yet they do opposite jobs. The dividing line is pulse duration: a long pulse heats its target over milliseconds, while a Q-switched pulse fires in nanoseconds and breaks pigment apart mechanically. One is built for hair, blood vessels and nail fungus; the other for tattoos and pigment. They are not interchangeable.
This guide explains why, using the physics of pulse duration and the way each pulse interacts with skin, so you can match the machine to the indication instead of assuming "Nd:YAG" means one thing.
Same wavelength, opposite jobs: it comes down to pulse duration
Conclusion first: wavelength decides what the laser can reach, and pulse duration decides what it does once it gets there. Both long-pulse and Q-switched Nd:YAG lasers emit at 1064 nm, and many add a 532 nm option, so both penetrate to similar depths. What changes is how long the energy is delivered. In HONKON device manuals, the long-pulse 1064B runs pulse widths up to 50 ms, while the Q-switched 1064Q fires a single pulse of about 6 ns. That is a difference of millions of times, and it flips the tissue effect from thermal to photoacoustic.
The framework behind this is selective photothermolysis, the theory Anderson and Parrish proposed in 1983. It holds that a laser destroys a target selectively when the pulse is matched to the target's size and its thermal relaxation time. Long pulses suit larger, deeper targets that hold heat, such as a hair follicle or a blood vessel. Ultra-short pulses suit tiny pigment particles that must be broken apart before heat can spread to the surrounding skin.
What a long pulse Nd:YAG laser does
A long pulse Nd:YAG laser works by heat. Over a millisecond-scale pulse, 1064 nm light is absorbed by haemoglobin in blood vessels and by the pigment and structures of the hair follicle, raising their temperature enough to coagulate the vessel or damage the follicle while the surrounding skin stays intact. HONKON's 1064B literature describes exactly this selective absorption by haemoglobin and the follicular bulb, paired with sapphire contact cooling to protect the epidermis.
Its typical indications:
- Hair removal, especially on darker skin (Fitzpatrick IV to VI), where 1064 nm is favoured because it largely bypasses epidermal melanin.
- Vascular lesions such as leg veins, telangiectasia and some facial vessels.
- Nail fungus (onychomycosis), where the aim is to heat the nail plate and bed rather than to break up a pigment.
- Skin rejuvenation and gentle collagen heating.
For hair and vessels, see our complete hair removal solution; for the fungus application, see the long pulse Nd:YAG laser for fungus.
Why nail fungus is a long-pulse job
Nail fungus laser treatment is a thermal, long-pulse task. The beam passes through the nail plate and heats the nail bed enough to suppress the fungus, rather than shattering anything. Older HONKON device literature describes the nail surface reaching roughly 50 degrees Celsius in short bursts to inhibit fungal growth, a photothermal and photochemical mechanism, not a photoacoustic one.
Set expectations honestly with buyers and patients. In the United States, the FDA has cleared long-pulsed 1064 nm Nd:YAG systems for a "temporary increase of clear nail" in people with onychomycosis, not for a guaranteed cure, and published clinical work often pairs the laser with oral antifungals. A Q-switched laser is the wrong tool here: its nanosecond pulse cannot deliver the sustained heat the nail bed needs.
What a Q-switched Nd:YAG laser does
A Q-switched Nd:YAG laser works by a photoacoustic shockwave, not by heat. Its nanosecond pulse deposits energy into a pigment particle faster than the heat can spread, so the particle absorbs a huge power spike and fractures. HONKON's 1064Q manual describes this as an "instantaneous blast" that shatters pigment into fragments; some are pushed out of the skin and the rest are cleared by phagocytes and the lymphatic system. Because the pulse is so brief, there is almost no thermal damage to the surrounding tissue.
Its typical indications:
- Tattoo removal across several ink colours, using 1064 nm for dark inks and 532 nm for red.
- Pigmented lesions such as nevus of Ota, freckles, cafe-au-lait macules and age spots.
- Carbon-peel style rejuvenation.
See our tattoo removal solution and the Q-switched Nd:YAG laser for the pigment side of the family.
Long pulse vs Q-switched Nd:YAG at a glance
| Feature | Long pulse Nd:YAG | Q-switched Nd:YAG |
|---|---|---|
| Pulse duration | Milliseconds (up to about 50 ms) | Nanoseconds (about 6 ns) |
| Primary effect | Photothermal (sustained heat) | Photoacoustic (shockwave) |
| Main targets | Haemoglobin, hair follicle, nail bed | Pigment particles, tattoo ink |
| Typical uses | Hair removal, vascular lesions, nail fungus | Tattoo and pigment removal |
| Wavelengths | 1064 nm (often 532 nm too) | 1064 nm and 532 nm |
| Skin heating | High; needs epidermal cooling | Minimal |
Why you cannot swap one for the other
Using the wrong pulse duration either wastes the shot or harms the skin. Fire a Q-switched nanosecond pulse at a hair follicle or a leg vein and the energy is gone before the target heats up, so little useful happens. Fire a long millisecond pulse at a tattoo and you bulk-heat the skin instead of fracturing the ink, risking a burn or scar with poor clearance. The target's thermal relaxation time is the dividing line, and no amount of extra power moves a machine to the other side of it.
Some platforms offer both modes in one cabinet, which is convenient, but they remain two separate tools that happen to share a housing. Buy for the indications you actually treat.
How to choose: a quick checklist
- Treating hair, veins or nail fungus? Choose a long pulse Nd:YAG.
- Removing tattoos or pigment? Choose a Q-switched (or picosecond) Nd:YAG.
- Doing both? Look for a verified dual-mode platform, and read each mode's specs separately.
- Serving darker skin tones? 1064 nm is the safer wavelength for hair.
- Compare pulse width, spot-size range and cooling in the spec sheet, not just the wavelength.
Frequently Asked Questions
Is a long pulse Nd:YAG laser the same as a Q-switched laser?
No. They share the 1064 nm wavelength but differ in pulse duration and effect. A long pulse lasts milliseconds and heats its target, which suits hair, vessels and nail fungus. A Q-switched pulse lasts nanoseconds and shatters pigment, which suits tattoos and pigmented lesions. The wavelength is the same; the job is not.
Can I remove a tattoo with a long pulse Nd:YAG laser?
Not effectively, and it can be risky. Tattoo ink needs a nanosecond or picosecond photoacoustic pulse to fracture the particles. A long millisecond pulse mostly heats the skin around the ink, which raises the chance of a burn or scar while clearing little pigment. Use a Q-switched Nd:YAG for tattoos and stubborn pigment.
Does laser cure nail fungus?
Laser is best described as a temporary aid, not a guaranteed cure. The FDA clears long-pulsed 1064 nm Nd:YAG lasers for a "temporary increase of clear nail" in onychomycosis, and studies often combine the laser with oral antifungals. Results vary between patients, several sessions are usual, and honest expectation-setting matters.
Why is 1064 nm used for darker skin?
The 1064 nm wavelength is absorbed relatively weakly by epidermal melanin and penetrates deeper, so it can reach a hair follicle or vessel while sparing pigmented skin at the surface. That makes long pulse 1064 nm Nd:YAG a common choice for hair removal on Fitzpatrick IV to VI skin, where shorter wavelengths carry more risk.
Pmise Technical Team. We manufacture and export laser and light-based aesthetic systems, and write from hands-on device manuals and clinical training material rather than spec-sheet copy.
