Method and Apparatus for Selecting an Optimum Write Parameter, and Optical Recording Medium for Use by Said Method and Apparatus

A method for setting an optimum value of a write parameter for use in an optical recording apparatus for writing information on an optical recording medium (1) by means of a radiation beam (5), the method comprising the steps of:

• 1) writing a series of test patterns on the recording medium, each pattern being written with a different value of a write power level (P) of the radiation beam,
• 2) reading the patterns so as to form corresponding read signal portions (18, 19),
• 3) deriving a value of a read parameter from each read signal portion,
• 4) curve-fitting a function defining a relation between the read parameter and the write power level (P), to associated values of the read parameter and the write power level (P), the curve-fitting function having a initial value of write power level (Pini,),
• 5) obtaining a characteristic write power level (Pchar) from the curve-fitting function, and assessing if the characteristic write power level (Pchar) qualify as an optimum value of a write parameter, and if the characteristic write power level (Pchar) does not qualify as an optimum value of a write parameter then start
• 6) obtaining one or more characteristic write power levels (Pchar, n) by an iteration procedure where the subsequent initial values of write power level (Pini, n), are given by
• Pini, n+1=APini, n+(1−A)Pchar, n,
• where A is a constant, and n is an integer.