Jorge Casares Velázquez 2 July 2020 at 12:38 To: Toshihiko Kimura Cc: Vik Dhillon , Manuel Torres Hi Toshihiko, Don’t worry, there is no rush. I did a preliminary calibration of the filters, using your simulated transmissions for the f/2.4 case of NTT+ULTRACAM and I obtain an excellent recovery of the FWHM of model lines (see botom panel in the attached figure). Basically, the recovered values are excellent for a wide range of line intensities (EW=10-150 Angs) and down to ~200 km/s or 0.4 nm, that is, 0.3% of the width of the very narrow Halpha filter, which is great. Next step will be to repeat the calibration using the “mesured" transmission curves of the actual filters, but modified by the f/2.4 focal ratio, but as i said, there is no rush. Early next week I’ll contact you for an optical design of a new version of the filters, to be installed in JPCam, on the T25 telescope of Javalambre Observatory. In this case the filters are larger (102x97mm) but the focal ratio is also larger (f/3.64) which may help. Cheers, Jorge AVISO LEGAL: Este mensaje puede contener información confidencial y/o privilegiada. Si usted no es el destinatario final del mismo o lo ha recibido por error, por favor notifíquelo al remitente inmediatamente. Cualquier uso no autorizadas del contenido de este mensaje está estrictamente prohibida. Más información en: https://www.iac.es/es/responsabilidad-legal DISCLAIMER: This message may contain confidential and/or privileged information. If you are not the final recipient or have rec eived it in error, please notify the sender immediately. Any unauthorized use of the content of this message is strictly prohibited. More information: https://www.iac.es/en/disclaimer El 2 jul 2020, a las 11:28, Toshihiko Kimura escribió: Dear Prof. Casares, I'm deeply sorry for my slow response. Of course, I never forget to do it, but I am very busy (from last week). I will calculate as soon as possible. Regards, Toshihiko On 2020/06/19 19:33, Jorge Casares Velázquez wrote: Hi Toshihiko, I think I understand what you say. Basically is to run again your simulations for the f/2.3 case but using now the in-built filter’s responses that you have measured for the actual filters in a parallel beam. That would be great, could you please do that? I also understand that there may be an issue with the refractive index for the broad filters, but this is not important for the Halpha very narrow filter, which is the most affected by the f/2.3 ratio. So, I believe this will be the best approach to get the real filter’s response on ULTRACAM. Cheers, Jorge El 19 jun 2020, a las 11:18, Toshihiko Kimura escribió: Dear Prof. Dhillon, Prof. Casares, First of all, Prof. Dhillon, thank you so much for your suggestion to Prof. Casares for me. This is my complemental suggestion. > The transmission will also be slightly different in a f/2.3 beam > compared to a parallel beam I completely agree you in extremely broad filter. "Thanks to" extremely broad band-width, negative effects by an f/2.3 beam is very small. I also agree you in very broad filter, but it seems to me negative effects are more than extremely broad in terms of deterioration of sharpness of slopes in passband. But I am not an astronomer, so I'm not sure how they impact your science. It seems to me that negative effects are significant in very narrow filter. However again, I'm not sure how they impact your science. I think we could probably simulate the transmission curve in an f/2.3 beam with *as-built* filters in a parallel beam. But we could apply only one refractive index to the simulation, hence, I don't think it is reliable for a broad band, e.g. Sloan r-band filter. However, more critical filter here is very narrow filter, so I think only one refractive index is not bad. How about the following? a)Use our simulated transmission curves in an f/2.3 beam with as-built filters b)Regarding CWL in an f/2.3 beam, use the number provided by me. Because each shift number calculated by computer is more reliable with "variable" refractive index at each wavelength. I'm afraid my suggestion is not clear to you. If there is something to be clarified, please let me know. Regards, Toshihiko On 2020/06/19 0:37, Vik Dhillon wrote: Hi Jorge, I can try to answer this question on behalf of Toshihiko.... As I understand it, Asahi are only able to make measurements of *as-built* filters in a *parallel* beam. They can't measure it for arbitrary f-ratio beams incident on the filters. So you can either: 1. Take the as-built, parallel beam curves and shift the bandpasses by the amounts given in Toshihiko's previous email. (The shift should be approximately constant across the whole filter bandpass, so it is fine to simply subtract a constant shift, I believe.) The transmission will also be slightly different in a f/2.3 beam compared to a parallel beam, although I believe this should be less of an issue for your simulations. Or 2. Take the simulated f/2.3 curves and shift the central wavelengths to the as-built values, as you suggest. I suspect doing item 1 might be better, although it might be useful to try both and see how they compare? Cheers, Vik. --- Prof. Vik Dhillon, Dept of Physics & Astronomy, Univ of Sheffield, Sheffield S3 7RH, UK +44 114 222 4528; www.vikdhillon.staff.shef.ac.uk --- On Thu, 18 Jun 2020 at 11:18, Jorge Casares Velázquez wrote: Hi Toshihiko, Thank you for sending me the measured transmission curve of the Halpha very narrow filter. It is true that you already sent the transmission curves on Dec 16 for the f/2.3 ULTRACAM system, but these were only simulations, while the transmission curves that you are sending now are actual measurements on the manufactured filters, although for a parallel beam. Therefore, for the best description of the actual filter performance I think I should better take your simulated transmission curves from 16 Dec (which do include the effect of the filter shape degradation by the 12.55 deg beam of the f/2.3 system), BUT shifting the CWL so to make these 655.70 nm for the Halpha very broad filter, 655.99 nm for the Halpha very narrow filter and 655.97 nm for the Halpha extremely broad filter, as computed by your engineer on the message sent on May 27, do you agree? Cheers, Jorge El 18 jun 2020, a las 7:43, Toshihiko Kimura escribió: Dear Prof. Casares, > in order to run my simulations with the actual transmission curves > provided by Toshihiko for ULTRACAM I should have mentioned about the influence to such narrow band filter by a fast beam. Regarding very/extremely broad filter, it is not necessary to consider it so much. However, I think it is necessary for you to consider it (e.g. band shape, FWHM, or peak transmission) as well as "bluer shift of CWL" in your simulation. I sent the simulation data in an f/2.3 beam to Prof. Dhillon and you on 16 December, last year. Sincerely, Toshihiko On 2020/06/18 15:25, Toshihiko Kimura wrote: Dear Prof. Dhillon, Prof. Casares, I send the actual transmission data of the Halpha very narrow filter for the HiPERCAM today. > The size of the HiPERCAM filter is 50 mm x 50 mm, not large. > However, we measured the transmission at 5 locations over the clear > aperture in consideration of the requested CWL tolerance, +/-0.5 nm. As the Halpha very broad filter, we measured the transmission at five locations over the clear aperture. [HiPERCAM Halpha very narrow filter] In a parallel beam at AOI 0 deg, Location 1 CWL: 657.8 nm / FWHM: 2.8 nm Location 2 CWL: 657.8 nm / FWHM: 2.8 nm Location 3 CWL: 657.8 nm / FWHM: 2.8 nm Location 4 CWL: 657.8 nm / FWHM: 2.8 nm Location 5 CWL: 657.6 nm / FWHM: 2.8 nm Averaged CWL of 5 locations is 657.76 nm. > 657.76 - 1.53 = 656.23 nm in an f/2.47 beam at HiPERCAM + WHT > 657.76 - 0.77 = 656.99 nm in an f/3.465 beam at HiPERCAM + GTC > 657.76 - 1.77 = 655.99 nm in an f/2.3 beam at ULTRACAM Halpha very narrow filter meets our proposed specifications including out-of-band transmission. Sincerely, Toshihiko On 2020/05/29 15:07, Toshihiko Kimura wrote: Dear Dr. Torres, CC Prof. Dhillon, Prof. Casares, I will send the actual transmission data of the Halpha extremely broad (35 nm) filter for the HiPERCAM today. > In consideration of requested wavelength tolerance and 35 nm FWHM, > or filter size, we measured the transmission only at the center location. CWL is 658.30 nm and FWHM is 35.0 nm in a parallel beam. > 658.30 - 2.01 = 656.29 nm in an f/2.47 beam at HiPERCAM + WHT > 658.30 - 1.02 = 657.28 nm in an f/3.465 beam at HiPERCAM + GTC > 658.30 - 2.33 = 655.97 nm in an f/2.3 beam at ULTRACAM The peak transmission exceeds 99%. And the shape of passband is perfect, like "top-hat". Halpha extremely broad filter meets our proposed specifications including out-of-band transmission completely. Sincerely, Toshihiko From: Toshihiko Kimura Sent: Monday, May 25, 2020 3:27 PM To: mapt@iac.es Cc: Vik Dhillon ; Jorge Casares Velázquez Subject: Actual transmission data(HiPERCAM Halpha very broad filter) Dear Dr. Torres, CC Prof. Dhillon, Prof. Casares, According to the DHL tracking page, the customs clearance was completed last Thursday. > The IAC has started to handle the reception of some goods on Thursdays > and in the morning. I hope the package will be delivered to the IAC on 28 May. By the way, I will send the actual transmission data of the Halpha very broad (15 nm) filter for the HiPERCAM today. I asked our staff to mark each filter-name on one edge for identification. The size of the HiPERCAM filter is 50 mm x 50 mm, not large. However, we measured the transmission at 5 locations over the clear aperture in consideration of the requested CWL tolerance, +/-0.5 nm. You can get the same transmission performance by the incident beam from both directions. [HiPERCAM Halpha very broad filter] In a parallel beam at AOI 0 deg, Location 1 CWL: 658.0 nm / FWHM: 15.2 nm Location 2 CWL: 657.8 nm / FWHM: 15.2 nm Location 3 CWL: 658.0 nm / FWHM: 15.2 nm Location 4 CWL: 658.0 nm / FWHM: 15.2 nm Location 5 CWL: 658.0 nm / FWHM: 15.2 nm Averaged CWL of 5 locations is 657.96 nm. => 657.96 - 1.95 (bluer shift) = 656.01 nm in an f/2.47 beam at the HiPERCAM (Spec: 656.3 nm +/-0.5 nm in an f/2.47 beam) The peak transmission exceeds 99%. And the shape of passband is definitely perfect. Halpha very broad filter completely meets our proposed specifications including out-of-band transmission. Sincerely, Toshihiko From: Toshihiko Kimura Sent: Monday, December 16, 2019 11:48 AM To: Vik Dhillon Cc: Jorge Casares Velázquez Subject: Quotation(New Halpha filters for HiPERCAM) Dear Prof. Dhillon, I will send a quotation about new Halpha filters (very narrow, very broad, extremely broad) for the HiPERCAM today. I quoted 2 pcs for each, but on the basis of the optimization for an f/2.47 beam at the HiPERCAM. Halpha very narrow filter is quite sensitive for angle of incidence due to very narrow band-width. Eventually, peak transmission in an f/2.3 beam (ULTRACAM) is lower than in an f/2.47 beam. I'm now aware that I asked our engineer to make transmission model on the basis of f/2.45 beam, but it should be an f/2.47 beam. I think the difference is negligible, but just in case, I will ask him to check, especially about very narrow Halpha. [Proposed Specifications] 1)Coating method Magnetron sputtering method 2)CWL Very narrow: 656.3 nm +/-0.3 nm in an f/2.47 beam Very broad: 656.3 nm +/-0.5 nm in an f/2.47 beam Extremely broad: 656.3 nm +/-1 nm in an f/2.47 beam 3)FWHM We would like to suggest the FWHM specification in a parallel beam. Very narrow: 2.7 nm +/-0.3 nm in a parallel beam => 3.4 nm +/-0.3 nm in an f/2.47 beam Very broad: 14.9 nm +/-1 nm in a parallel beam => 15.0 nm +/-1 nm in an f/2.47 beam Extremely broad: 35.1 nm +/-3 nm in a parallel beam => 35.0 nm +/-3 nm in an f/2.47 beam 4)Peak transmission We would like to propose the specification of peak transmission for all in a parallel beam. T > 90% in a parallel beam 5)Blocking T < 0.01% 300 nm - 1100 nm 6)Substrate Monolithic fused silica 7)Size 50 mm x 50 mm +0, -0.1 mm 8)Clear aperture 48 mm x 48 mm 9)Thickness 5.43 mm +/-0.025 mm 10)Parallelism < 30 arc sec 11)Transmitted wavefront error (TWF) p-v lambda/4 per any 25 mm patches over the clear aperture prior to coating Our Zygo laser interferometer is equipped with HeNe laser (632.8 nm). But HeNe laser doesn't transmit through the Halpha filters, thus it is not possible to measure the TWF after coating. But thanks to a monolithic substrate structure, the initial TWF will be maintained after coating. 12)Scratch-dig 60-40 Sincerely, Toshihiko ------------------------------------------------------ > From: Vik Dhillon > Sent: Friday, November 15, 2019 9:07 PM > To: Toshihiko Kimura ; Casares Jorge > Subject: New Halpha filters for HiPERCAM > > > Dear Toshihiko, > > I hope all is well with you. > > My colleague, Prof. Jorge Casares (Instituto de Astrofisica de Canarias) > and I would like to buy a new set of Halpha filters for HiPERCAM. I think > I will be the person who will pay for the filters. > > These filters should be the same dimensions and specifications as the > existing "Super-SDSS" HiPERCAM filters that you made for us. This includes > being the same optical thickness as our existing filters so that the focus > doesn't change when we switch between the Super-SDSS filters and these new > Halpha filters. > > We would like the new Halpha filters to have the following central > wavelength and FWHM: > > - Halpha very narrow: FWHM=3.3 +- 0.3 nm CWL=656.3 +- 0.3 nm > - Halpha very broad: FWHM=15.0 +- 1.0 nm. CWL=656.3 +- 0.5 nm > - Halpha extremely broad: FWHM=35.0 +- 3.0 nm CWL=656.3 +- 1.0 nm > > (I name them like this because you have previously supplied me with > "Halpha narrow" FWHM=5.4nm and "Halpha broad" FWHM=9.3nm). > > I realise that some of these filters have quite challenging tolerances! > > We would like to buy 2 of each of these filters, assuming this is > approximately the same price as buying just 1 of each? Please could you > provide us with a quotation for these filters? > > Regards, > > Vik. > > --- > Prof. Vik Dhillon, Dept of Physics & Astronomy, Univ of Sheffield, > Sheffield S3 7RH, UK > +44 114 222 4528; www.vikdhillon.staff.shef.ac.uk > ---