blaze

...Figure 2 is a typical example, where most of the diffracted light is concentrated in a certain range centered on the direction in which the incident light is specularly reflected by the groove surface. α in the figure is called the blaze angle, and the wavelength at which the intensity of the primary light is at its maximum is called the blaze wavelength, but the latter is often defined as the wavelength of the primary diffracted light that returns in the same direction when the incident light is perpendicular to the groove surface. A coarse echelette grating of (several hundred to several tens of lines)/mm is created for the ultraviolet and visible ranges, and the steep slope side is used as in Figure 3, which is called an echelle. ...

*Some of the terminology explanations that mention "blaze" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…図2はその代表例であり，入射光が溝面で正反射する方向を中心とするある範囲に回折光の大部分が集中する。図のαをブレーズblaze角，一次光の強度が最大となる波長をブレーズ波長と呼ぶが，後者は溝面に垂直に入射光を入れたとき同方向に戻る一次回折光の波長で定義することが多い。紫外･可視域に対して(数百～数十本)/mmの粗いエシェレット格子を作り，図3のように急斜面側を使うようにしたものをエシェルechelleという。…

※「blaze」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報