Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)

Ho:YAG and Tm:YAG lasers emitting at wavelengths of 2010 nm and 2100 nm are widely used for medical applications. LAYERTEC offers optical coatings for this wavelength range with high laser-induced damage thresholds and long lifetimes.

Cavity Mirrors

Fig.1:Reflectance spectra of cavity mirrors:

a)HR cavity mirror

b)Pump mirror with high transmittance around 808 nm

HR cavity and pump mirrors with R > 99.9 %
High laser-induced damage thresholds

Turning Mirrors

Fig.2:Reflectance spectra of turning mirrors for:

a)2010 nm

b)2100 nm

The coating materials are chosen to guarantee high laser-induced damage thresholds. To achieve the maximum reflectance for p-polarization, mirrors should be specified for either 2010 nm or 2100 nm.

Turning mirrors with R > 99.9 % for s-polarized light and
R > 99.8 % for p-polarized light at AOI = 45°
High laser-induced damage thresholds

Output Couplers

Fig.3:Reflectance spectrum of an output coupler with
R = 82 % ±1 % at 2100 nm

Output couplers with precisely adjusted degrees of reflectance:
- R > 95 % ±0.5 %
- R = 80 … 95 % ±1 %
- R = 10 … 80 % ±2 %

Edge Filters

Fig.4:Reflectance spectrum of a cavity mirror for 2010 nm suppressing the 2100 nm line

Fig.5:Reflectance spectrum of a steep edge filter for the separation of the 2010 nm and 2100 nm lines

Thin Film Polarizers

Fig.6:Reflectance spectra of a thin film polarizer for 2010 nm with
Rs > 99.8 %, Rp < 2 %, AOI = 55°

Separation of the s- and p-polarized component of the light (s-polarized light is reflected, p-polarized light is transmitted)
Thin film polarizers designed at Brewster’s angle (≈ 55°) exhibit a higher Tp/Ts ratio and a considerably broader bandwidth than those at AOI = 45°

Windows and Lenses

Lens materials according to customer specifications:
- Fused Silica with low OH-content, like Corning 7979^®, Infrasil^®,Suprasil^® 3001/3002/300
- Sapphire and undoped YAG
- Special AR coatings for high index materials such as GGG on request

Fig.7:Reflectance spectra of typical antireflection coatings:

a)Single wavelength AR coating for 2010 nm

b)Broadband AR coating 2010 – 2100 nm

c)Dual wavelength AR coating for the pump and laser wavelength (808 nm + 2010 nm)

Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)