Laser Line Dielectric Mirrors

What Is a Laser Mirror

Laser mirrors are advanced, precision optical mirrors designed for incorporation into laser systems. Laser mirrors steer, deliver, or fold laser lights. Since laser mirrors are purposed for laser applications, the mirrors must have premium accuracies, precision-engineered optical coatings to ensure the optimum total throughput efficiencies and the intended reflectance at the laser-specific wavelength or a certain wavelength range, and a high laser damage threshold to withstand the intense laser energies. However,  as the structure of a laser system can be complex, different sections of a laser system need different laser mirror types, and the actual requirements and designs of the laser mirrors are different depending on their application scenarios.

What is a Laser Line Dielectric Mirror

A laser line dielectric mirror is a subdivision of laser mirrors. Laser line dielectric mirrors are made of dielectric coatings deposited on optical substrates; the substrate material, the coating design depend on the needs of the application scenario, whether the laser mirror is used for beam folding, beam extraction, or as output couplers. Laser line means that the mirror has: 1) if the mirror is a laser line high reflection mirror, then it has high reflectivities within a very narrow band centered around the laser fundamental or harmonic wavelengths. 2) or a designed ratio of reflection: transmission at the DWL in the case of an output coupler. In comparison with metallic mirrors, dielectric mirror coatings often consist of structured dielectric thin films, allowing more flexible engineering for the reflectivities and transmissities of laser mirrors, and elevated laser induced damage threshold, therefore are preferred for laser cavities requiring minimized loss/absorption of optical powers and outstanding endurance to exposure to laser beams of high energies or laser pulses of high powers.

The Structures of Laser Systems and Laser Mirror Types Used

The basic structure of a laser system is a pumping source, a laser gain medium, a laser resonator cavity, and other accessories like isolators or filters. Laser mirrors are critical optical components in lasers, used to control beam direction, form laser resonator cavities, and shape the optical path.

Laser mirrors can be divided into the following types according to their functions and characteristics:

1. High reflection (HR) laser line mirrors: 

The main purpose of a high-reflective laser line mirror is to reflect laser beams with very high efficiencies (often close to 100%) at the laser wavelengths and with low loss, while withstanding high laser powers. Due to the high reflectance required, the coating is often dielectric. The applications of high reflector laser mirrors are manifold. This is how highly reflective laser line mirrors work: they can be a laser resonator end mirror to bounce the photons back and forth to generate resonance and create amplification of the laser, or used for beam steering (i.e., changing the direction of a laser beam) or beam folding (Bending the beam path so the optical setup takes up less space). 

Some applications like femtosecond lasers require low dispersion properties of the HR laser mirrors and high laser damage to withstand the massive peak powers, where low GDD, high power coatings are essential. For ultrafast laser applications, low GDD laser mirrors optimized with low dispersion for femtosecond lasers or ultrafast lasers are available. You can check the off-the-shelf stock list on this page.

2. Output coupler mirror: 

The laser output coupler is also a kind of laser line mirror, often being partially reflective (i.e., allowing a portion of the laser wavelength to pass through and reflecting the remaining back to the laser cavity). The OC mirrors are positioned at the light exciting terminals of the laser cavities.

3. Harmonic Separators

Laser harmonic separators are a kind of dichroic laser mirrors to separate harmonic wavelengths from the fundamental laser wavelength.

The mirrors' shapes are also different depending on the mirror design. For the most part, laser mirrors are flat mirrors; curved mirrors, such as convex or concave mirrors, are chosen for special needs, including stabilizing the cavities (ensuring the beam doesn’t diverge or collapse), controlling beam waist size and location, and optimizing the laser mode structure (e.g., single-mode vs multi-mode).

Shalom EO - Supplier of Laser line Dielectric mirrors

Hangzhou Shalom EO is a professional supplier of laser mirrors. This page specializes in our laser line dielectric mirrors; we can provide both off-the-shelf and custom laser line dielectric mirrors. The laser mirrors are perfected based on our combination of high-precision processing of mirror substrates and our IAD e-beam thin film coating techniques to realize the excellent coating design. (You can also click here to learn more about Shalom EO's optical coating capabilities).

Shalom EO’s off-the-shelf laser line dielectric mirrors:

Shalom EO provides a wide selection of standard dielectric laser mirrors: these are high-reflective laser mirrors with diameters ranging from 12.7mm to 50.8mm. The narrowband laser wavelength-specific dielectric mirror modules highlight >99.8% reflectivities at 0° or 45° angle of incidence, high laser-induced damage threshold of >20J/cm2@1064nm,10ns, 10Hz pulse or 10J/cm2@755nm, 10ns, 10Hz pulse, with surface flatness of λ/10. Broadband laser line mirror modules for AOI at 0-45°  are also available. You can find diverse wavelengths suitable for various laser types: 1) Nd:YAG laser line mirrors: 4th harmonic wavelength~1064nm; 2)HeNe laser line mirror: 633nm; 3)Alexandrite laser mirrors: 755nm; 4)mirror for LD laser wavelength: 808nm; 5)more...

In addition, we offer low GDD mirrors for femtoline lasers; the GDD values of these mirrors are ±20fs2. The mirrors are excellent for Ti:sapphire and ytterbium ultrafast lasers. 

Hangzhou Shalom EO also provides standard and custom output couplers and harmonic separators for ultrafast lasers. Click on the blue bold texts to learn more.

Shalom EO’s custom laser line dielectric mirrors:

With flexible coating abilities and ion beam assisted e-beam (IAD e-beam) coating technologies, Hangzhou Shalom EO can deliver various laser line dielectric coatings catering to your needs. 

Shalom EO’s Standard Laser Line Dielectric Mirrors:

1. High Reflection Laser Line Mirrors

Standard specs as follows, or other custom specs.:

Standard wavelenth options for HR laser line mirrors:

2. Low GDD Femtosecond Laser Mirrors

Standard specs as follows, or other custom specs.:

3. Output Couplers

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4. Ultrafast Output Couplers

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