What are the achievements of poetry in Han Dynasty?

This period was called the "conscious period" of literature by Lu Xun. His main achievements in poetry are: five-character poems have developed from formation to prosperity, seven-character poems have developed from origin to initial development, and the genre of miscellaneous poems and short poems of five, seven and four sentences has also matured. The new prosodic theory was gradually applied to poetry creation, which laid the foundation for the development of modern prosodic poetry after the Tang Dynasty. Literary criticism, including poetry criticism, has also achieved unprecedented development and prosperity. Besides Cao Pi's Dian Lun Wen and Lu Ji's Wen Fu, Liu Xie's Wen Xin Diao Long has many chapters devoted to poetry, and Zhong Rong's Shi Pin is a systematic monograph on poetry.