Mirror coatings

One of the most widespread types of coatings is the reflecting dielectric mirror coating for the fixed wavelength. ELAN offers mirrors for various wavelengths inside 250 - 2000 nm wavelength range.

 The spectral characteristic of standard mirror for 1064 nm and an angle of incidence 0 ° is shown on  the figure 1. The damage threshold of the coating is 20 - 25 J/cm².

Fig. 1 Dielectric mirror coating for 1064 nm, AOI = 0° (normal incidence)

 The spectral curves of standard mirrors for 1550 nm with angle of incidence of 0° and 45° are shown in figures 2 and 3 accordingly.

Fig. 2 Dielectric mirror coating for 1550 nm AOI = 0° (normal incidence)

Fig. 3 Dielectric mirror coating for 1550 nm, AOI = 45°

 At present time ELAN offers dielectric mirror coatings for femtosecond pulsed lasers with working wavelength 800 ± 50 nm, thus high coefficient of reflection R > 99.9 % is provided in all range of wavelengths by one mirror.

 The characteristics of dielectric mirrors for femtosecond pulsed lasers with angle of incidence of 0° and 45° are shown in figures 4 and 5 accordingly.

Fig. 4 Dielectric mirror coating for 800±50 nm, AOI=0° (normal incedence)

Fig. 5 Dielectric mirror coating for 800±50 nm, AOI=45°

The development of laser technology requires the usage of mirrors designed for two or more wavelength as well as the usage of mirrors working under various angles of incidence and in a range of various angles.
The spectral characteristic of a mirror for wavelength 532nm and 1064 nm, for an angle of 0° is shown in graph 6.

Fig. 6 Dual band dielectric mirror coating for 532 and 1064 nm, AOI = 0° (normal incidence)

The characteristics of dielectric mirrors for 1064 nm (R> 99 %) with simultaneous reflection for 650 nm (R> 80 %), with angles of incidence of 30° - 50° are shown in figures 7, 8 and 9.

Fig. 7 Dual band dielectric mirror coating for 650 and 1064 nm, AOI = 30°

Fig. 8 Dual band dielectric mirror coating for 650 and 1064 nm, AOI = 45°

Fig. 9 Dual band dielectric mirror coating for 650 and 1064 nm, AOI = 55°

ELAN has certain skills in fabrication of dielectric mirror coatings for various optical crystals. As an example, the mirror coating made on LiNbO₃ substrate for 1319 nm with high transmittance for a number of wavelength (712 nm, 1060 nm and 1550 nm) is shown on the figure 10.

Fig. 10 Dielectric mirror for 1319 nm with high transmittance at 712, 1060 and 1550 nm, AOI = 0° (normal incidence)