A response from Adam at Thorlabs to iddoheller: We currently test the mirrors up to 50 degrees C so we cannot guarantee performance at 100 degrees. If this relatively long-pulse laser emits a Gaussian 12.7 mm diameter beam (1/e2) at 980 nm, then the resulting output has a linear power density of 5.9 W/cm and an energy density of 1.2 x 10-4 J/cm2 per pulse. I am using Nd-YAG laser, 1064nm, 7ns, 10Hz repetition rate. This can be compared to the LIDT values for a WPQ10E-980 polymer zero-order quarter-wave plate, which are 5 W/cm for CW radiation at 810 nm and 5 J/cm2 for a 10 ns pulse at 810 nm. In the reflectance plots for 45 deg AOI, isn't it true that the unpolarized curves have to be the average of the p- and s- polarized curves? Next, the power/energy is either increased or decreased and the optic is exposed at 10 new locations. It would be helpful if you add the 45 and 0 degree reflectivity curve together in the plot. Good day. Thanks. Please note that we have a buffer built in between the specified damage thresholds online and the tests which we have done, which accommodates variation between batches. Hello Xiaodong, thank you for contacting Thorlabs. We are worried about surface figure in a particular length range (300um to 5mm) that we don't think is captured effectively by a single surface accuracy number. There are deformable mirrors, where the surface shape can be controlled, often with many degrees of freedom (possibly several thousands). Circular polarization is maintained upon reflection; however, the handedness is reversed (i.e. A good rule of thumb is that the damage threshold has a linear relationship with wavelength such that as you move to shorter wavelengths, the damage threshold decreases (i.e., a LIDT of 10 W/cm at 1310 nm scales to 5 W/cm at 655 nm): While this rule of thumb provides a general trend, it is not a quantitative analysis of LIDT vs wavelength. Metallic mirrors cannot be used because they will heat and fused. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately [3]. Hello Dirk, thank you for contacting Thorlabs. Response from Bweh at Thorlabs USA: We have some theoretical data regarding the phase shift at 45 deg angle of incidence that I will share with you via email. The number of locations that are damaged at a particular power/energy level is recorded. My apologies for the inconvenience caused by this. hello, could you please provide me with the more detailed information about E02 coating product including
You must now adjust this energy density to account for hotspots or other nonuniform intensity profiles and roughly calculate a maximum energy density. If so, is it s- or p- polarized? While we do not have a single mirror coating with a different reflectance from the front and back, it sounds like you might be trying to build a circulator.
Absorption is either due to an intrinsic property of the optic or due to surface irregularities; thus LIDT values are only valid for optics meeting or exceeding the surface quality specifications given by a manufacturer. Hello,
Note that the performance of the coating outside the designed spectral range is not guaranteed and will vary from one coating run to another. They are used in lasers with unstable resonators, also as variable optical attenuators. Good day, I want to use mirror to reflect HeNe laser placed in a set-up in which oscillating magnetic field in the kHz to MHz frequency is present. While most mirrors have a uniform reflectance across their reflecting area, there are also variable reflectivity mirrors, where the reflectance depends on the position. best regards
Beam diameter = Ø0.433 mm
Testing may result in additional costs or lead times. Response from Bweh E at Thorlabs: It is possible to have this on silicon wafers. Dielectric mirrors function based on the interference of light reflected from the different layers of dielectric stack. Dielectric mirrors exhibit retardance as a function of angle of incidence and mirror design.[1]. I am going to use the E03 coating for Ti:Sapphire laser (routing mirrors to my set-up)
Are you looking for the s- and p- reflectivity data at AOI > 45 deg? However, we have not done tests at this temperature to confirm this yet. cos θ in the tangential plane and (R / 2) / cos θ in the sagittal plane. They clearly aren't. In particular, one can learn about the power of exponential growth and the threshold behavior. Best,
Upon request, we can provide individual test information and a testing certificate. Im specifically interested in the reflectance of the 423 nm wavelength in this mirror. Pulse width = 10 ns
We do not sell this as a stock item at the moment, but we can provide it as a custom. AT 780 nm, we can estimate that the damage threshold will be lower by about 25%. Please note that the performance of the coating is rather inconsistent outside the designated range and we cannot guarantee that your mirror will perform as the data suggests. Upon request, we can provide individual test information and a testing certificate. Hello, is it possible to get the information for the phase shift for E02 coating for the working spectral band and a few AOI or data (transfer matrix) to simulate it on my own. It would also be helpful to have the know the material and thickness of the multilayer coatings (perhaps an index versus distance from the blank mirror plot?).