$first order spectrum diffraction grating$

FIRST ORDER SPECTRUM DIFFRACTION GRATING FREE

Gratings in this table are listed by laser type. The maximum ruled area is groove length x ruled width. The gratings below are suitable for use in the specific molecular lasers indicated. For this type of application, we suggest you advise us of the following specifications: There are a number of masters available which are used to produce replicas with high S-plane efficiency for use with CO 2, CO, HF, or DF lasers (see below). Master Grating Options for Molecular Laser Tuning Water-cooled gold replica on copper 200 W/cm 2.Standard gold replica on copper 100 W/cm 2.Standard gold replica gratings can withstand 300 mJ/cm 2 pulses of 100 ps duration.In all cases, close attention to groove geometry maximizes reflection, minimizes absorption, and leads to improved grating performance. The informati0on below serves as a guide to the typical power levels a grating can be expected to survive. In the case of cw lasers, replicas on metal substrates are superior to glass because of greater thermal conductivity in some cases it is advisable to use water cooled substrates.

$first order spectrum diffraction grating$

In the case of pulsed lasers, extra thick replica films may be of help. Some molecular lasers operate at high power, capable of destroying gratings. For maximum efficiency, any of these gratings can be supplied in the form of gold replicas. This is a consequence of the electromagnetic nature of diffraction from deep groove gratings. Note from the master grating options below, which summarizes gratings most suitable for molecular laser tuning, that high efficiency corresponds to diffraction angles that can be significantly greater than the groove or blaze angles. The output will be polarized in the S-plane (i.e., with the electric vector perpendicular to the grooves) because the efficiency will be several times greater than in the P-plane (electric vector parallel to the grooves).ĭispersion is a function of the tangent of the diffraction angle b and is chosen from medium (b ≈ 20°) to very high (b > 50°) as required. This corresponds to l/d ratios from 0.67 to 1.8 (where d is the groove spacing), which ensures that only the zero and first orders can diffract. High efficiency is obtained by operating in the first order at diffraction angles >20°. Molecular lasers, operating both pulsed and continuous-wave (cw) in the infrared, typically have their output wavelength tuned by Littrow-mounted gratings. Gratings are used in these lasers to control and narrow the lasing wavelength. These high-power lasers generally produce gain over a wide spectral range. Molecular lasers have a wide variety of uses, ranging from materials processing to medical applications. Steep angle usage leads to special grating dimensions such as 16.5 x 58 x 10 mm. The gratings have their ruled width filled by incidence angles of 80° to 88°. Grazing incidence tuning is done in first order only and 1800 g/mm, 2000 g/mm, and 2400 g/mm holographic gratings are preferred.

FIRST ORDER SPECTRUM DIFFRACTION GRATING FREE

For the latter, a 600 g/mm, 54° blaze angle grating is particularly useful because it covers the visible spectrum in orders 3 to 7 with free spectral ranges that match the dyes and prevent overlap. Littrow tuning is done either with fine pitch, first order gratings (typically 1800 or 2400 g/mm frequency, either ruled or holographic) or a coarser grating used in higher orders. The alternative approach is to use the grating in a fixed grazing incidence mode together with a rotating reflecting tuning element in the form of either a mirror or a second grating.

$first order spectrum diffraction grating$

Telescope or prism optics fulfill this need. The classical one is with a grating in the autocollimating (Littrow) mount where the beam requires expansion to fill the grating in order to obtain adequate resolution. The combination of a diffraction grating and one of these dyes in a laser allows the production of laser light that has a narrow line width and which is tunable through the gain profile of the dye.ĭye laser wavelength tuning, in the visible region of the spectrum, is done in two different modes. Lasers that employ certain organic dyes as their gain media have the ability to lase over a broad range of frequencies.

$first order spectrum diffraction grating$

First order spectrum diffraction grating