Design A four-element astronomical telescope in SYNOPSYS

Here is an example to design a very good astronomical telescope for advanced amateur astronomers.The input file for DSEARCH is as follows:

CORE 14 
TIME 
DSEARCH 1 QUIET 
  SYSTEM 
  ID DSEARCH TELESCOPE 
  OBB 0 0.7 75 
  WAVL 0.6563 0.5876 0.4861 

  UNITS MM 
  END 
  GOALS 
  ELEMENTS 4 
  FNUM 8 
  TOTL 0 0 
  STOP FIRST 
  STOP FIX 
  TSTART 25 
  ASTART 50 
  RT 0 
  OPD 
  FOV 0.0 0.75 1.0 
  FWT 5.0 3.0 1.0 
  NPASS 40

  ANNEAL 50 10 Q 
  COLORS 3 
  SNAPSHOT 10 
  QUICK 40 40 
  END 
  SPECIAL PANT 

  END 
  SPECIAL AANT 
  ADT 7 .1 10 LUL 400 .1 1 A TOTL 
  END 
  GO 
TIME        

We want a telescope with extremely good image quality at F/8. This DSEARCH input will target only OPD errors in the real merit function (plus the usual monitors and first-order goals). Run this MACro, and DSEARCH returns the lens in about 11 seconds.

This is essentially perfect already, but it has model glasses, and we need to replace them with real glass. Run the optimization MACro prepared by DSEARCH, make a checkpoint, and then use MRG to replace them with glass from the Guangming catalog. The lens is just as good, but one of the elements received a very expensive glass. Can we achieve better quality and a lower price?

It is time to use another tool. Restore the checkpoint and save the optimization MACro with the name GSOPT.MAC.

Now make a new MACro to run GSEARCH, containing the following:

GSEARCH 3 QUIET 
SURF 
1 3 5 7 
END 
NEAREST 5 P 10 
G 
END 
GO        

Now the program will search 81 combinations of glass and only investigate glass types not more than ten times the price of BK7. The result is superb, after more optimization and annealing, shown as below.