Today, spectroscopic methods have attracted the attention of many researchers and industrialists for the identification and characterization of materials due to their many advantages over other analysis methods. Raman spectroscopy is one of the types of vibrational spectroscopy methods that are used in many fields such as biology, medicine, identification of drugs, petrology, 2D materials, semiconductors, protein materials, food, etc. Raman spectroscopy is a widely used, fast, accurate, and non-destructive method. Raman spectra contain valuable information about the molecular structure of materials. Raman microspectrophotometers, in addition to recording the Raman spectra of the micrometric points of the samples, can provide transmission and reflection imaging of the desired points.

Vibrational spectroscopy is a complete tool for identifying and determining the structure of organic compounds, including drugs, food, polymer materials, explosives, etc. When talking about vibrational spectroscopy, usually the name of infrared method comes to mind, not Raman spectroscopy. In recent decades, there has been a development in the Raman method, especially in its instrumental part. These developments have led to its unique applications in various industries. This article deals with theory, instrumentation, sampling methods and applications of Raman spectroscopy.

Bioactive materials including glass and glass-ceramics are nowadays used as medical implants for orthopedic applications. In this study several samples of glass-ceramics have been prepared using both heat treatment and sol-gel processes. The structure and bioactivity of these samples based on their interaction with simulated body fluid (SBF) have been determined, invitro, using the Raman spectroscopic technique. It is found that most samples exhibit bioactivity when they are soaked in SBF. It is also concluded that Raman spectroscopy is a powerful technique in such studies.

Raman spectroscopy as a partner to infrared spectroscopy is now a well developed technique for structural and analytical investigations. This article is concerned with recent developments in the technique of Raman spectroscopy, i.e., the Raman microprobe or Raman microscope. This technique makes possible meaningful studies of small microscopic particles (about 1- mu m in diameter) and only a nano-liter of a liquid or even a picogram of a solid sample. Examples of Raman spectra of very small size samples of a wide range of materials such as biological systems, polymers, fibers, etc., are given and the results are interpreted on the basis of vibrational Raman spectroscopy. It is concluded that the Raman microscope is a unique non-destructive method of microchemical analysis.

Silver selenide (Ag2Se) thin films of thickness between 80 and 160 nm were prepared by thermal evaporation method. From XRD studies, the structure of the prepared film is confirmed to exhibit orthorhombic structure with polycrystalline nature. The average grain size of Ag2Se has been determined as 43 nm. EDAX spectra of these films were taken, and its composition ratio has been analyzed. Micro-Raman spectra of bulk and their films have been recorded with He-Ne laser source at room temperature. Raman peaks are observed at 232, 455, 566 and 815 cm-1. These peaks are assigned to their corresponding modes of vibrations.