Apparatus for wavelength resolved angular resolved cathodoluminescence
Apparatuses for collection of wavelength resolved and angular resolved cathodoluminescence (WRARCL) emitted from a sample exposed to an electron beam (e-beam) or other excitation beams are described. Cathodoluminescence light (CL) may be emitted from a sample at specific angles relative to the excitation beam and analyzed with respect to light-emitting and other optical phenomena. The described embodiments allow collection of WRARCL data more efficiently and with significantly fewer aberrations than existing systems.
1. An apparatus for collection and analysis of wavelength-resolved and sample-emission-angle-resolved cathodoluminescence (CL) light emitted by a sample comprising:
a collection-mirror configured such that CL light collected by said collection-mirror forms a two-dimensional light-pattern representing light intensity as a function of angles of emission of the CL light with respect to the sample;
where said collection-mirror has a symmetric axis and an asymmetric axis; and
an image conduit onto which said two-dimensional light-pattern is projected,
wherein said image conduit is configured to permit only a portion of said two-dimensional light pattern to be received by a spectrograph, the portion being oriented along said asymmetric axis, and
wherein said image conduit is oriented to receive the portion of said two-dimensional light pattern along said asymmetric axis.
2. The apparatus of claim 1 , further comprising:
a translating fold-mirror configured to scan said two-dimensional light pattern over said image conduit to collect a wavelength-resolved and sample-emission-angle-resolved CL light dataset.
3. The apparatus of claim 1 wherein a translating fold-mirror is configured to scan said two-dimensional light pattern over said image conduit to collect a wavelength-resolved and sample-emission-angle-resolved CL light dataset.
4. A method of collection and analysis of wavelength-resolved and sample-emission-angle-resolved cathodoluminescence (CL) light comprising:
directing CL light to a collection-mirror configured such that CL light collected by said collection-mirror forms a two-dimensional light-pattern representing light intensity as a function of angles of emission of the cathodoluminescence light;
where said collection-mirror has a symmetric axis and an asymmetric axis;
projecting said two-dimensional light-pattern onto an image conduit;
configuring said image conduit to permit only a portion of said two-dimensional light pattern to be received by a spectrograph, the portion being oriented along said asymmetric axis; and
orienting said image conduit to receive the portion of said two-dimensional light pattern along said asymmetric axis.
5. The method of claim 4 , further comprising:
scanning said two-dimensional light pattern over said image conduit with a translating fold-mirror to collect a wavelength-resolved and sample-emission-angle-resolved CL light dataset.
6. The method of claim 4 , further comprising:
scanning said two-dimensional light pattern over said image conduit with a translating fold-mirror to collect a wavelength-resolved and sample-emission-angle-resolved CL light dataset.