Optical properties

	Refractive index n versus wavelength at four different temperatures. (Icenogle et al. [1976]).
	Refractive index n versus photon energy. T = 300 K. (Philipp and Taft [1959]).
	Reflectance versus photon energy. T = 300 K. (Cordona et al. [1967]).
	Low-level absorption spectrum of high purity Ge at various temperatures. (Macfarlane et al. [1957]).
	The absorption edge at three different temperatures (Seysyan et al. [1968]).
	The absorption coefficient versus photon energy. T = 300 K. (Phillipp and Taft [1959]).
	The absorption coefficient at different donor (As) concentrations. T = 300 K (Pankove and Aigrain [1962]).
	Intrinsic absorption edges at different donor (As) concentrations at 300 K obtained after substracting the free carrier absorption from the measured values. (Pankove and Aigrain [1962]).
T = 293 K.	The absorption coefficient at different acceptor (Ga) concentrations. (Bagaev et al. [1962]).
	Intrinsic absorption edge at different doping (Ga) level T = 293 K. (Bagaev et al. [1962]).
	Free carrier absorption versus wavelength at different doping levels. n-Ge. T = 300 K. Conduction electron concentration: no(cm-1): 1. 8.0·1017; 2. 4.8·1018; 3. 1.35·1019; 4. 1.8·1019; 5. 3.6·1019. (Fistul [1967])
	Free carrier absorption versus photon energy at different doping levels. p-Ge. T = 300 K. Free hole concentration: po(cm-3): 1. 7.3·1015; 2. 1.6·1016; 3. 6.0·1016; 4. 1.9·1017; 5. 1.2·1018; 6. 1.0·1019. (Ukhanov [1977] and Vasilyeva et al. [1967]).

Two-photon absorption coefficient β